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 ofthe Circle, 
the Chord length, 
the Arc Length, 
the height of the arced portion, and 
theheight 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) |
References
Beyer, W. H. (Ed.) CRC Standard Mathematical Tables, 28th ed. Boca Raton, FL: CRC Press, p. 125, 1987.
- Euler Triangle Formula
- Euler Walk
- Euler Zigzag Number
- Eutactic Star
- Evans Point
- Eve
- Even Function
- Even Number
- Eventually Periodic
- Everett Interpolation
- Everett's Formula
- Eversion
- Evolute
- Exact Covering System
- Exact Differential
- Exactly One
- Exactly When
- Exact Period
- Exact Trilinear Coordinates
- Excenter
- Excenter-Excenter Circle
- Excentral Triangle
- Excess
- Excess Coefficient
- Excessive Number