Circle theorems (OCR GCSE Maths): Flashcards

Diameter is twice the radius ($d = 2r$)

Exactly one point

Centre angle = $2 \times$ circumference angle

$90\degree$ (right angle)

Equal to each other

$180\degree$

$90\degree$ (right angle)

Equal to angle in alternate segment

Equal in length

Line segment connecting two points on circumference

Part of the circumference of the circle

Quadrilateral with all vertices on circle's circumference

Circumference angle is $90\degree$ (semi-circle)

Area between a chord and the circumference

Isosceles triangle