Do you still remember all the properties of circles in IGCSE/GCSE Maths?

**Properties of Circles**

1. Perpendicular bisector of any chord always passes through the centre of the circle.

2. Where a tangent meets a radius the angle between them is always 90º.

3. Tangents from same point are always equal in length to where they touch the circle.

4. An angle in a semi circle is always 90º (When a triangle goes through the centre, where it hits the circumference = 90º).

5. The angle subtended at centre is twice angle at circumference.

6. Angles in the same segment, subtended by the same arc/chord are equal.

7. Opposite angles of a cyclic quadrilateral add to 180º/supplementary.

8. Alternate Segment theorem ⟶ the angle between a tangent and a chord is equal to the angle subtended by the chord in the alternate segment.

That's the end of the topic!

Drafted by Bonnie (Mathematics)