# Examples about circumference of a circle

**Example: ****A rectangular wire has a 132-meter
perimeter. A circle is formed by twisting the same wire. The circumference
formula can be used to calculate the radius of a circle.**

**Solution:**

The perimeter of the rectangle
equals the total length of the wire utilized, which equals the circumference of
the circle produced.

As a result, the circle formed has a
circumference of 132 meters.

The formula for calculating the
circumference of a circle = 2 πr

132 is the circle's circumference.

To find the radius, we can substitute the known values.

132 = 2r

132 = 2 (22/7) r

132 = 44/7 r

r = 21 meters

Thus, the circle's radius is 21 meters.

**Understand this concept by using an
example:**

**Example: ****Umar completed four laps of a
circular track. What is the diameter and radius of the field if he ran a total
distance of 500 m?**

**Solution:**

Umar completed one laps of circular
field = 500 / 4 =125

The circumference of a circular
field is 125 meters.

Diameter of circular field =
circumference / π

Diameter of circular field =
125/3.14= 39.81meters

Radius of circular field =
circumference / 2π

Radius of circular field =

**Example****: Circular parks have a 70-meter
diameter. At $2 per meter, calculate the cost of fencing it.**

**Solution:**

The park has a 70-meter diameter.

The radius of the circle is

r= 70/2 = 35metres

A meter of fencing costs $2.

The circumference of the circular
park is the length covered by fencing.

The park's circumference is

=2 π r

= 2 (22/7) x 35 = 220 meters

Fencing has a cost = 220

**Example: On one of his new apartment's walls,
Jasmin is painting a big circle. The circle will be 49 feet in diameter at its
widest point. What is the approximate area that the circle will cover on a
wall?**

**Solution:**

We are finding an area if you are asked to calculate the number of square feet covered by something. To calculate the area of Jasmin's circle, we must first determine if the radius or the diameter has been given. The diameter of a circle is defined as the longest distance across it, hence the diameter is 49 feet in this case. The radius is 7 feet in this case. Therefore:

A= π

As a result, Jasmin's circle will
encircle approximately 154 square feet of his property.

**Example:**** A birthday party was held in a
circular lounge. The diameter of the circular lounge is 14 yards. What is the
area of the circular lounge?**

**Solution:**

The diameter of circular lounge = 14
yards

We want to find the area of the
circular lounge

Firstly we will find the radius of a
circular lounge from diameter, as we know

Radius = diameter/2

r = 14/2 = 7 yards

By applying the circle’s area
formula

As a result, the area of the
circular lounge is 154 yards.