Geometry & Trigonometry
Intermediate

Sector Area (Radians)

Area of a circular sector with angle in radians.

Formula

A=12r2θA = \frac{1}{2}r^2\theta

Variables

rRadius
\thetaAngle (rad)

Example

Half of r-squared times angle

Did You Know?

A radian is the angle that makes an arc as long as the radius, so a full circle is exactly 2π radians.

circlesector