Mathematics & Statistics / Geometry
Circle Sector Area Calculator
Formula
Area = (π × r² × angle) / 360
Calculate the area of a circle sector from radius and angle for geometry, design, and engineering layout tasks.
Formula
Sector Area = (theta / 360) * pi * r^2
Worked Example
radius10
angleDegrees90
Result: 78.54 square unitsA 90-degree sector is one quarter of a circle, so area is one quarter of full circle area.
Frequently Asked Questions
Can I use radians instead of degrees?
Yes, if supported by input mode. In radian form, area is (1/2) * r^2 * theta.
How is sector area different from arc length?
Sector area measures enclosed region size; arc length measures the curved boundary distance.