Segment Area Calculator

Find the area of a circular segment from radius and central angle.

Segment area 7.135

Formula: area = ½ r²(θ − sin θ), θ in radians

Step-by-step with your numbers:
1. Values used:
2. Radius = 5
3. Central angle = 90 °
4.
5. Segment area = 7.135
Did we solve your problem today?

A circular segment is the region between a chord and the arc it cuts off.

The math behind it

area = ½ r²(θ − sin θ), where θ is the central angle in radians. It equals the sector area minus the triangle area.

Worked example

Radius 5, angle 90° → ½·25·(π/2 − 1) ≈ 7.13.

FAQ

Segment vs sector?

A sector is the pie slice; a segment removes the triangle, leaving just the cap beyond the chord.