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Basic Geometry

Basic Geometry

Perimeter & Circumference Examples

Example 1

What is the circumference of a circle with diameter 12 cm?

Circle (4)

To find the circumference we need to multiply the diameter by π.

c= d (pi) = 12 (pi)

c = 12 x 3.14

c = 37.68 cm or 12 (pi)

Example 2

Find the circumference of a circle with a radius of 3 cm.

Circle (5)

Example 3

Find the radius of a circle with circumference of 31.4 cm.

Circle (6)

In this problem we need to work backwards to find the radius. We start by plugging in the information we know:

c = d (pi)

31.4 = d x (pi)