Angles in rectangles and squares with algebra | GCSE / IGCSE Maths

Geometry and measuresKey Stage 3

Solve an equation for two angles that share a right-angled corner.

The two marked parts of the corner add to .
Collect like terms, then solve for .

Example 1

Find at the corner of the rectangle.

A corner of a rectangle or square is a right angle: 90°.

Apply this to both sides.

A corner of a rectangle or square is a right angle: 90°.

Apply this to both sides.

Example 2

Find at the corner of the square.

A corner of a rectangle or square is a right angle: 90°.

Apply this to both sides.

A corner of a rectangle or square is a right angle: 90°.

Apply this to both sides.

Your turn

Question 1

Find at the corner of the rectangle.

Check answer

A corner of a rectangle or square is a right angle: 90°.

Apply this to both sides.

A corner of a rectangle or square is a right angle: 90°.

Apply this to both sides.

Question 2

Find at the corner of the square.

Check answer

A corner of a rectangle or square is a right angle: 90°.

Apply this to both sides.

A corner of a rectangle or square is a right angle: 90°.

Apply this to both sides.

Question 3

Find at the corner of the rectangle.

Check answer

A corner of a rectangle or square is a right angle: 90°.

Apply this to both sides.

A corner of a rectangle or square is a right angle: 90°.

Apply this to both sides.

Question 4

Find at the corner of the square.

Check answer

A corner of a rectangle or square is a right angle: 90°.

Apply this to both sides.

A corner of a rectangle or square is a right angle: 90°.

Apply this to both sides.

Question 5

Find at the corner of the rectangle.

Check answer

A corner of a rectangle or square is a right angle: 90°.

Apply this to both sides.

A corner of a rectangle or square is a right angle: 90°.

Apply this to both sides.