Question

a wire in the form of a rectangle with dimensions 70 cm and 40 cm is bent into the form of a circle. find the diameter of the circle.

Answer 1

Let the diameter of the circle be D

Here Lenght of the wire = Perimeter of Rectangle

Or length of wire = 2(L+B)

= 2( 70cm + 40cm)

=220cm

Since this wire is bent to shape a circle

Therefore Perimeter of circle (Circumference) = length of wire

πD = 220cm ( ∵ circumference = 2πr or πD)

Putting π=22/7

$\frac{22}{7}D=220 cm$

D = (220×7)/22 cm

D= 70 cm

Hence, diameter of the circle is 70 cm

Answer 2

Step-by-step explanation:

length of wire = 2(L+B)

= 2( 70cm + 40cm)

=220cm

Since this wire is bent to shape a circle

Therefore Perimeter of circle (Circumference) = length of wire

πD = 220cm ( ∵ circumference = 2πr or πD)

Putting π=22/7

\frac{22}{7}D=220 cm

7

22

D=220cm

D = (220×7)/22 cm

D= 70 cm is the right answer