Arc area, arc length, chord length calculator

Radius (r):
Arc angle (a):
Arc area:
Arc length:
Chord length:

1. Circle area = π * r2

2. Circle circumference = 2 * π * r

3. Arc area (shaded) = r2 * (a - sin(a)) / 2

4. Arc length = r * a

( Note: The unit is radians.)