Find the area of a circular segment from a radius and a central angle.
Last updated: June 2026 | By Patchworkr Team
Enter the radius and angle as real numbers.
A circular segment is the region between a chord and its corresponding arc.
That formula uses theta in radians, so degrees are converted before calculation.
1. Enter the radius and the central angle.
2. Pick degrees or radians for the angle input.
3. Read the live area result in the right-hand panel.
For r = 6 and theta = 90 degrees:
theta = pi/2
A = 1/2 * 36 * (pi/2 - 1) ≈ 10.29
The formula itself uses radians, so degrees are converted automatically.
No. The tool rejects invalid angles and uses the correct segment formula.
Angles must be strictly between 0 and 2π radians after conversion.
Yes, the formula is valid for the provided central angle segment.
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