CIRCUMFERENCE OF A CIRCLE

You now know that π = Circumference or π = _C_

Diameter

D

Using simple algebra, you will find that the formula can be written C = π D or

Circumference = π x Diameter

Find the length of the circumference of a circle when the diameter is equal to 2

inches.

C = D π D

C = 3.14 x 2 inches

C = 6.28 inches

In this problem we simply substituted in the formula C = π D and solved by

multiplying.

You solve these problems:

(1) Find the circumference of a circle when the diameter equals 10 inches.

C = π D

(2) Find the circumference when the diameter equals 7 inches.

(3) Find the diameter when the circumference equals 6.2832 feet.

D = _C_

π