A cyclic quadrilateral is a quadrilateral where all four of its vertices lie on a single circle.

The opposite angles of a cyclic quadrilateral sum to 180°

Maths

In the prior unit, pupils applied their understanding of angles to solve increasingly complex problems. In this unit, pupils will use their developed mathematical reasoning skills to derive and use various circle theorems.

Circle theorems

The size of the angle labelled $$a$$° is {{}}°.

The size of the angle labelled $$d$$° is {{}}°.

The size of the angle labelled $$e$$° is {{}}°.

Find the size of angle $$g$$° (in degrees).

The size of the angle labelled $$b$$° is {{}}°.

The size of the angle labelled $$c$$° is {{}}°.

∠PEF is subtended by the chord PF.
∠PFE is subtended by the chord PE.
Find ∠EPD (in degrees).

This lesson will soon be taken down.

The opposite angles of a cyclic quadrilateral sum to 180°

Lesson outcome