Geometry & Trigonometry
Basic

Area of a Circle

The area enclosed by a circle.

Formula

A=πr2A = \pi r^2

Variables

rRadius

Example

r = 5 → A = 25π ≈ 78.54

Did You Know?

Archimedes proved the area of a circle by squeezing it between inscribed and circumscribed polygons — an early form of calculus.

circleareageometry