# Circumference and Area of a Circle

In this lesson, we are required to find both the circumference and the area of the circle given its radius or diameter.

**Formulas to find the circumference and the area of a circle**

Circumference of a circle is given by the formula C = 2πr where π = 3.14 and r is the radius of the circle

Area of a circle is given by the formula A = πr

^{2}where π = 3.14 and r is the radius of the circle.

Find the area and circumference of following circle. Use π = 3.14

### Solution

**Step 1:**

Given radius r = 9.5 units

**Step 2:**

Circumference of Circle, C = 2πr = 2(3.14)9.5 = 59.66 units

**Step 3:**

Area of Circle, A = πr^{2} = (3.14)(9.5)(9.5) = 283.39 square units

Find the area and circumference of following circle. Use π = 3.14

### Solution

**Step 1:**

Given diameter = 4; radius r = 4/2 = 2 units

**Step 2:**

Circumference of Circle, C = 2πr = 2(3.14)2 = 12.56 units

**Step 3:**

Area of Circle, A = πr^{2} = (3.14)(2)(2) = 12.56 square units