[highlight]
[ul]
[li]A sector is a fraction of the area of a circle[/li]
[li]an arc is a fraction of the circumference of a circle[/li]
[/ul]
[code]area = [pi]r[squared] [r = radius][/code]
[code]circumference = [pi]d [d = diameter][/code]
[/highlight]
Area of a sector:
[code]
([theta] [divide] 360) [multiply] [pi]r[squared] [where [theta] is the angle of the sector of the circle]
[/code]
