In the circle above, the radius has a length of 3, so the circumference is 2π(3) = 6π.
94 . Length of an Arc
An arc is a piece of the circumference. If n is the degree measure of the arc’s central angle, then
the formula is
In the figure above, the radius has a length of 5, and the measure of the central angle is 72
degrees. The arc length is of the circumference:
95 . Area of a Circle
Area of a Circle = πr^2