# Equation for Circumference of a Circle

## Online Tutoring Is The Easiest, Most Cost-Effective Way For Students To Get The Help They Need Whenever They Need It.

We can say circumference of the circle is the actual length around the circle. We have an equation or formula to find the circumference of the circle, that is 2 x π x r. Here r is the radius of the circle. And we know the value of the π that is 3.14 or22/7.

Example 1: Find the circumference of the circle with radius 21 cm.

Solution: From the problem we can write,

Radius = r = 21 cm

We know the formula to find the Circumference of the circle

That is C = 2 x π x r

Now we can plug the value in this formula, then we can write

Circumference of the circle=C = 2 x π x r

From this we can write

C = 2 x π x r = 2 x 22/7 x 21 = 132 cubic cm.

Example 2: Find the circumference of the circle with diameter 28 cm.

Solution: From the problem we can write,

Diameter = d = 28 cm

We know the formula to find the Circumference of the circle

That is C = 2 x π x r

Now we can plug the value in this formula, then we can write

Circumference of the circle=C = 2 x π x r

From this we can write

C = 2 x π x r = 2 x 22/7  x 14 = 4 x 22 = 88 cubic cm.