PG.3B, SEC 1, Angles in rhmbs, parlgrm, trpzm (50)

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Trapezium with one line of symmetry: copy the diagram, use the symmetry line to match equal angles, then use the 360° total in a quadrilateral to find the missing one.

First copy the trapezium and label the given angle and the matching equal angle using the line of symmetry.

Use the symmetry to write the equal pairs, like c = b and a = d, because mirrored corners match.

Then use 360° for the full quadrilateral to build one equation and solve for the missing angle.

symmetry facts: mirrored angles are equal
so: c = b and a = d
angles in any quadrilateral total 360°
then: a + b + c + d = 360°
substitute: a + b + b + a = 360°
so: 2a + 2b = 360°
so: 2a = 360° − 2b
then: a = (360° − 2b) ÷ 2

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Trapezium with one line of symmetry: copy the diagram, use the symmetry line to match equal angles, then use the 360° total in a quadrilateral to find the missing one.

First copy the trapezium and label the given angle and the matching equal angle using the line of symmetry.

Use the symmetry to write the equal pairs, like c = b and a = d, because mirrored corners match.

Then use 360° for the full quadrilateral to build one equation and solve for the missing angle.

symmetry facts: mirrored angles are equal
so: c = b and a = d
angles in any quadrilateral total 360°
then: a + b + c + d = 360°
substitute: a + b + b + a = 360°
so: 2a + 2b = 360°
so: 2a = 360° − 2b
then: a = (360° − 2b) ÷ 2

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Trapezium with one line of symmetry: copy the diagram, use the symmetry line to match equal angles, then use the 360° total in a quadrilateral to find the missing one.

First copy the trapezium and label the given angle and the matching equal angle using the line of symmetry.

Use the symmetry to write the equal pairs, like c = b and a = d, because mirrored corners match.

Then use 360° for the full quadrilateral to build one equation and solve for the missing angle.

symmetry facts: mirrored angles are equal
so: c = b and a = d
angles in any quadrilateral total 360°
then: a + b + c + d = 360°
substitute: a + b + b + a = 360°
so: 2a + 2b = 360°
so: 2a = 360° − 2b
then: a = (360° − 2b) ÷ 2

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Trapezium with one line of symmetry: copy the diagram, use the symmetry line to match equal angles, then use the 360° total in a quadrilateral to find the missing one.

First copy the trapezium and label the given angle and the matching equal angle using the line of symmetry.

Use the symmetry to write the equal pairs, like c = b and a = d, because mirrored corners match.

Then use 360° for the full quadrilateral to build one equation and solve for the missing angle.

symmetry facts: mirrored angles are equal
so: c = b and a = d
angles in any quadrilateral total 360°
then: a + b + c + d = 360°
substitute: a + b + b + a = 360°
so: 2a + 2b = 360°
so: 2a = 360° − 2b
then: a = (360° − 2b) ÷ 2

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Trapezium with one line of symmetry: copy the diagram, use the symmetry line to match equal angles, then use the 360° total in a quadrilateral to find the missing one.

First copy the trapezium and label the given angle and the matching equal angle using the line of symmetry.

Use the symmetry to write the equal pairs, like c = b and a = d, because mirrored corners match.

Then use 360° for the full quadrilateral to build one equation and solve for the missing angle.

symmetry facts: mirrored angles are equal
so: c = b and a = d
angles in any quadrilateral total 360°
then: a + b + c + d = 360°
substitute: a + b + b + a = 360°
so: 2a + 2b = 360°
so: 2a = 360° − 2b
then: a = (360° − 2b) ÷ 2

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Trapezium with one line of symmetry: copy the diagram, use the symmetry line to match equal angles, then use the 360° total in a quadrilateral to find the missing one.

First copy the trapezium and label the given angle and the matching equal angle using the line of symmetry.

Use the symmetry to write the equal pairs, like c = b and a = d, because mirrored corners match.

Then use 360° for the full quadrilateral to build one equation and solve for the missing angle.

symmetry facts: mirrored angles are equal
so: c = b and a = d
angles in any quadrilateral total 360°
then: a + b + c + d = 360°
substitute: a + b + b + a = 360°
so: 2a + 2b = 360°
so: 2a = 360° − 2b
then: a = (360° − 2b) ÷ 2

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Trapezium with one line of symmetry: copy the diagram, use the symmetry line to match equal angles, then use the 360° total in a quadrilateral to find the missing one.

First copy the trapezium and label the given angle and the matching equal angle using the line of symmetry.

Use the symmetry to write the equal pairs, like c = b and a = d, because mirrored corners match.

Then use 360° for the full quadrilateral to build one equation and solve for the missing angle.

symmetry facts: mirrored angles are equal
so: c = b and a = d
angles in any quadrilateral total 360°
then: a + b + c + d = 360°
substitute: a + b + b + a = 360°
so: 2a + 2b = 360°
so: 2a = 360° − 2b
then: a = (360° − 2b) ÷ 2

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Trapezium with one line of symmetry: copy the diagram, use the symmetry line to match equal angles, then use the 360° total in a quadrilateral to find the missing one.

First copy the trapezium and label the given angle and the matching equal angle using the line of symmetry.

Use the symmetry to write the equal pairs, like c = b and a = d, because mirrored corners match.

Then use 360° for the full quadrilateral to build one equation and solve for the missing angle.

symmetry facts: mirrored angles are equal
so: c = b and a = d
angles in any quadrilateral total 360°
then: a + b + c + d = 360°
substitute: a + b + b + a = 360°
so: 2a + 2b = 360°
so: 2a = 360° − 2b
then: a = (360° − 2b) ÷ 2

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Don’t include this line!

Don’t include this line!

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Trapezium with one line of symmetry: copy the diagram, use the symmetry line to match equal angles, then use the 360° total in a quadrilateral to find the missing one.

First copy the trapezium and label the given angle and the matching equal angle using the line of symmetry.

Use the symmetry to write the equal pairs, like c = b and a = d, because mirrored corners match.

Then use 360° for the full quadrilateral to build one equation and solve for the missing angle.

symmetry facts: mirrored angles are equal
so: c = b and a = d
angles in any quadrilateral total 360°
then: a + b + c + d = 360°
substitute: a + b + b + a = 360°
so: 2a + 2b = 360°
so: 2a = 360° − 2b
then: a = (360° − 2b) ÷ 2

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Trapezium with one line of symmetry: copy the diagram, use the symmetry line to match equal angles, then use the 360° total in a quadrilateral to find the missing one.

First copy the trapezium and label the given angle and the matching equal angle using the line of symmetry.

Use the symmetry to write the equal pairs, like c = b and a = d, because mirrored corners match.

Then use 360° for the full quadrilateral to build one equation and solve for the missing angle.

symmetry facts: mirrored angles are equal
so: c = b and a = d
angles in any quadrilateral total 360°
then: a + b + c + d = 360°
substitute: a + b + b + a = 360°
so: 2a + 2b = 360°
so: 2a = 360° − 2b
then: a = (360° − 2b) ÷ 2

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Trapezium with one line of symmetry: copy the diagram, use the symmetry line to match equal angles, then use the 360° total in a quadrilateral to find the missing one.

First copy the trapezium and label the given angle and the matching equal angle using the line of symmetry.

Use the symmetry to write the equal pairs, like c = b and a = d, because mirrored corners match.

Then use 360° for the full quadrilateral to build one equation and solve for the missing angle.

symmetry facts: mirrored angles are equal
so: c = b and a = d
angles in any quadrilateral total 360°
then: a + b + c + d = 360°
substitute: a + b + b + a = 360°
so: 2a + 2b = 360°
so: 2a = 360° − 2b
then: a = (360° − 2b) ÷ 2

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Trapezium with one line of symmetry: copy the diagram, use the symmetry line to match equal angles, then use the 360° total in a quadrilateral to find the missing one.

First copy the trapezium and label the given angle and the matching equal angle using the line of symmetry.

Use the symmetry to write the equal pairs, like c = b and a = d, because mirrored corners match.

Then use 360° for the full quadrilateral to build one equation and solve for the missing angle.

symmetry facts: mirrored angles are equal
so: c = b and a = d
angles in any quadrilateral total 360°
then: a + b + c + d = 360°
substitute: a + b + b + a = 360°
so: 2a + 2b = 360°
so: 2a = 360° − 2b
then: a = (360° − 2b) ÷ 2

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Trapezium with one line of symmetry: copy the diagram, use the symmetry line to match equal angles, then use the 360° total in a quadrilateral to find the missing one.

First copy the trapezium and label the given angle and the matching equal angle using the line of symmetry.

Use the symmetry to write the equal pairs, like c = b and a = d, because mirrored corners match.

Then use 360° for the full quadrilateral to build one equation and solve for the missing angle.

symmetry facts: mirrored angles are equal
so: c = b and a = d
angles in any quadrilateral total 360°
then: a + b + c + d = 360°
substitute: a + b + b + a = 360°
so: 2a + 2b = 360°
so: 2a = 360° − 2b
then: a = (360° − 2b) ÷ 2

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Trapezium with one line of symmetry: copy the diagram, use the symmetry line to match equal angles, then use the 360° total in a quadrilateral to find the missing one.

First copy the trapezium and label the given angle and the matching equal angle using the line of symmetry.

Use the symmetry to write the equal pairs, like c = b and a = d, because mirrored corners match.

Then use 360° for the full quadrilateral to build one equation and solve for the missing angle.

symmetry facts: mirrored angles are equal
so: c = b and a = d
angles in any quadrilateral total 360°
then: a + b + c + d = 360°
substitute: a + b + b + a = 360°
so: 2a + 2b = 360°
so: 2a = 360° − 2b
then: a = (360° − 2b) ÷ 2

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Trapezium with one line of symmetry: copy the diagram, use the symmetry line to match equal angles, then use the 360° total in a quadrilateral to find the missing one.

First copy the trapezium and label the given angle and the matching equal angle using the line of symmetry.

Use the symmetry to write the equal pairs, like c = b and a = d, because mirrored corners match.

Then use 360° for the full quadrilateral to build one equation and solve for the missing angle.

symmetry facts: mirrored angles are equal
so: c = b and a = d
angles in any quadrilateral total 360°
then: a + b + c + d = 360°
substitute: a + b + b + a = 360°
so: 2a + 2b = 360°
so: 2a = 360° − 2b
then: a = (360° − 2b) ÷ 2

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Hint

💡 Symmetry rhombus angles: copy the diagram, use the symmetry marks to set equal angles, then use the 360° rule to share out the remaining angle.

First copy the rhombus and label the given angle a, the matching angle b, and the two unknown angles c and d.

Spot it is a rhombus because all four sides are equal and it is still a quadrilateral so the angles total 360°.

Use the symmetry marks to say a = b and c = d, then subtract the two known angles from 360° and split what is left between c and d.

angles in a quadrilateral total 360°
use symmetry: a = b and c = d
angle total: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: c = (360° − a − b) ÷ 2

Hint

💡 Parallelogram angles: copy the diagram, use the markings to set equal angles, then use angles on a straight line (180°) or around the shape (360°) to find the missing one.

First copy the parallelogram and label the given angle and the matching equal angle using the markings.

Use the fact that in a parallelogram opposite angles are equal and neighbouring angles add to 180°.

If the diagram shows pairs like a = b and c = d, write those down first, then use 360° for a full quadrilateral or 180° for a straight line to finish.

parallelogram facts: opposite angles are equal
neighbouring angles add to 180°
angles in any quadrilateral total 360°
use markings: a = b and c = d (if shown)
then: a + b + c + d = 360°
so: c + d = 360° − a − b
since c = d: d = (360° − a − b) ÷ 2

Hint

💡 Trapezium with one line of symmetry: copy the diagram, use the symmetry line to match equal angles, then use the 360° total in a quadrilateral to find the missing one.

First copy the trapezium and label the given angle and the matching equal angle using the line of symmetry.

Use the symmetry to write the equal pairs, like c = b and a = d, because mirrored corners match.

Then use 360° for the full quadrilateral to build one equation and solve for the missing angle.

symmetry facts: mirrored angles are equal
so: c = b and a = d
angles in any quadrilateral total 360°
then: a + b + c + d = 360°
substitute: a + b + b + a = 360°
so: 2a + 2b = 360°
so: 2a = 360° − 2b
then: a = (360° − 2b) ÷ 2