Area — Circles (AQA GCSE Maths): Flashcards

$A = \pi r^2$

$C = 2\pi r$ or $C = \pi D$

Radius is half the diameter

Portion of circle bounded by two radii and an arc

Curved edge of a sector

$\frac{x}{360} \times$ area of full circle

$\frac{x}{360} \times$ circumference of full circle

Region between a chord and arc it cuts off

Sector area minus triangle area

Curved arc and straight edges