Circle Theorems

Question 1

Theorem 19

Answer 1

The angle at the centre of a circle standing on a given arc is twice the angle at any point of the circle standing on the same arc.

Question 2

Corollary 2

Answer 2

All angles at points of a circle standing on the same arc are equal in measure.

Question 3

Cyclic`Quadrilateral definition

Answer 3

A quadrilateral in which all four vertices (corners) are points of a circle is referred to as a cyclic quadrilateral.

Question 4

Corollary 5

Answer 4

If ABCD is a cyclic triangle then opposite angles sum to 180 degrees.

Question 5

corollary 3

Answer 5

Each angle in a semicircle is a right angle