Circle theorems

Question	Answer
Image: 7c0c4996-d5f5-4747-95c7-09f5c66b8ffe (image/jpg)	The perpendicular bisector of any chord passes through the centre.
Image: dfac71f0-3435-4ab6-ac70-3036ebf181e5 (image/jpg)	The angle in a semicircle is always 90 degrees.
Image: 4ec0fec6-e405-4696-8a43-80373a878413 (image/png)	The radius and a tangent always meet at 90 degrees.
Image: 824c7d74-09be-4a83-b8ef-9e9a712afc79 (image/png)	Angles in the same segment are equal.
Image: e71453e5-ec7e-4e4b-abf3-249b0d26c5ed (image/jpg)	The angle at the centre is twice the angle at the circumference
Image: 6c7eae9c-c829-4708-86c2-3f310d286a9e (image/png)	Opposite angles of a cyclic quadrilateral add up to 180 degrees. x + y = 180 a + b = 180
Image: 465ad672-9bd1-4153-ae41-e48368fdce75.gif (image/gif)	The lengths of two tangents from a point are equal. AB = AC
Image: 2532edfd-3db1-4cce-9f04-9228c418e7b1 (image/png)	The angle between a tangent and a chord is equal to the angle in the alternate segment.

Resource summary

	Created by Jessica Alton over 8 years ago