- S5 geometry
- Angle in the same segment
- Angle at centre is twice the angle at the circumference v2
- Angle in the semi circle
- Perpendicular bisector of a chord passes through the centre.
- Equal chords are equidistant from the centre of the circle
- Congruent Chords and their Central Angles
- Ang in the opps segment.
- Exterior angle of a cyclic quadrilateral
- Converse of angle in alternate segment
- Angle between tangents from external point
