Angles in Cyclic Quadrilaterals Flashcards

All 5 cards in this deck

What is a cyclic quadrilateral?

A quadrilateral with all four vertices on the circumference of a circle.

State the circle theorem about the angles of a cyclic quadrilateral.

Opposite angles of a cyclic quadrilateral sum to $180^\circ$.

In a cyclic quadrilateral, what is the exterior angle equal to?

The opposite interior angle.

True or false? Opposite angles of a cyclic quadrilateral are equal.

False. They sum to $180^\circ$.

True or false? The opposite-angles theorem works for any quadrilateral drawn inside a circle.

False. All four vertices must lie on the circumference.