Circle Theorems

There are 8 circle theorems in total, and they’re all facts about angles/lengths in particular situations all involving circles.

1. The angle at the center is twice the angle at the circumference
2. The angle in a semicircle is a right angle
3. Angles in the same segment are equal
4. Opposite angles in a cyclic quadrilateral sum to 180°
5. The angle between the chord and the tangent is equal to the angle in the alternate segment
6. The perpendicular radius to the chord bisects the chord
7. The radius is perpendicular to the tangent
8. The tangents from a point to a circle are equal in length