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