- S4 Properties of Circle
- Angle at centre twice angle at circumference
- Angles in the same segment
- Perpendicular from centre to chord bisects chord
- Equal chords, equal arcs
- Chords equidistant from centre are equal
- Test for cyclic quadrilateral
- Opposite angles, cyclic quadrilateral
- Arcs proportional to angles at centre
- Arcs proportional to angles at circumference
- Angle in alternate segment
- Converse of Tangent perpendicular to radius
- Converse of angle in alternate segment
