## Sector

A Wedge obtained by taking a portion of a Circle with Central Angle radians (180°), illustrated above as the shaded region. A sector of radians would be a Semicircle. Let be the radius of the Circle, the Chord length, the Arc Length, the height of the arced portion, and the height of the triangular portion. Then

 (1) (2) (3) (4) (5) (6) (7) (8) (9)

The Angle obeys the relationships
 (10)

The Area of the sector is
 (11)

(Beyer 1987).