Circumference = πd
In the circle above, the radius is 3, so the circumference is 2π(3) = 6π.
FOUR CIRCLE FORMULAS
Circumference = 2πr = πd
Length of an
Area of a Circle = πr^2
Area of a
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: