1. Circumference of circle Application

2. Recap
The ratio of circumference to diameter is constant for all circles. This ratio is called Pi and is written as π. Where π = C = π ⇒
C = πd ⇒
C = 2πr d 22 7

3. Circumference of circle Application - Introduction
We know that perimeter is measuring the outside of any shape.
Let us learn how to calculate perimeter by small Illustration of using rope length.
Let us take a rope of x length and try reshaping the rope into a square as given below.
X length
From this, its clearly seen that Perimeter of a square = length of the rope.

4. Circumference of circle Application - Introduction
Now let us see 2nd illustration for Circle:
Let us take the same rope of x length and try reshaping it as a circle.
X length
What can you conclude from the illustration?
From the above illustration, we conclude that Circumference of a circle = length of the rope.
Therefore, if the rope of any particular length is reshaped into any shape , can become perimeter of that shape
(as far as circle, its circumference)

5. Given:- Length of the wire = 88cm To Find:- radius of circle
Example 1 : A wire of length 88 cm is bent as a circle. What is the radius of the circle.
Solution
Given:- Length of the wire = 88cm To Find:- radius of circle
Since the wire is bent to a circle
Circumference of circle = length of wire = 88cm
Circumference (C) = 2πr 2
Divide 88 and 44 by 44
= 14 cm (ans)

6. Try these
A wire of length 44 cm is bent as a circle. What is the radius of the circle?
A wire of length 110 cm is bent as a circle. What is the radius?