Sector Area Calculator
Find the area of a circular sector from its radius and central angle.
Inputs
units
°
Sector Area
78.5398sq units
Step by step
Apply sector area formula
A = ½ × 10² × 1.570796
= 78.5398
How it works
The area of a sector is a fraction of the full circle's area, proportional to the central angle.
Formula
Sector Area
A = ½ × r² × θ (θ in radians)
- r
- Radius
- θ
- Central angle in radians
Frequently Asked Questions
How is sector area related to circle area?
Sector area = (θ/360°) × πr². It's the proportional slice of the full area.
What is the sector area for a semicircle?
For θ = 180° (π radians): A = ½ × r² × π = πr²/2.