App description

AO and OB are called radius

AC, BC and AB are called strings

Angle ACB is the circumferential angle

Angle AOB is the center of the circle

The curved AB part is the arc arc.

OE is the edge distance

Triangle AOB is a triangle

ED is arch height

The arc length is calculated as: (Central Angle / 180°) • π • r

The yellow area is fan shaped

The fan area formula is: (Angle AOB / 360°) • π • r2

Green area is arched high area

This area size = sector area - AOB triangle

Usage example

Choose two parameters you know: radius and center angle

Radius: 5

Center angle: 30

Click "calculate" to output the result

Arch height ED: 0.17037

Edge center distance OE: 4.8296

String AB: 2.5882

Arc AB: 2.618

Perimeter: 31.416

Arch height area (green area): 0.29498

Area of triangle (AOB): 6.25

Sector area (yellow area): 6.545

Circular area: 78.54

Significant digits > > > 5