Circle Theorems II

What is Circle Theorems II?

The three symmetry properties of a circle required by Cambridge O Level Mathematics: chords of equal length are the same perpendicular distance from the centre; the perpendicular bisector of a chord passes through the centre, so the perpendicular dropped from the centre to a chord bisects it; and the two tangents drawn to a circle from the same external point are equal in length. All three follow from the circle's reflection symmetry rather than from any angle rule.

This definition is part of the Geometry chapter in Cambridge O Level Mathematics (Syllabus D).

Concepts related to Circle Theorems II

• chord distance
• perpendicular bisector
• equal tangents