Calculate angles where circles are involved
Circle Theorems
1. An angle subtended at the centre, is twice the angle subtended at edge
2. The angle at the edge of semi circle, subtended by the diameter, is always a right angle
3. Opposite angles in a quadrilateral, where all its corners are on the edge of a circle, sum to 180^{o }So in the below example D^{o }= 78^{o }and C^{o }= 63^{o }
4. Angles subtended on the same arc are equal
You will need to remember these theorems and be able to recognise them in order to solve problems.
Nothing in this section yet. Why not help us get started?
Related Topics
Requires a knowledge of…
After this move on to…
Related Questions

1Vote4Answers

2Votes5Answers

1Vote3Answers

1Vote2Answers

1Vote3Answers

0Votes4Answers

0Votes1Answer

0Votes1Answer

2Votes4Answers