Question

If the difference between the circumference and radius of a circle is 37 cm, then using π = \[\frac{22}{7}\] the circumference (in cm) of the circle is 

Options

•  154

•  44

• 14

• 7

Answer 1

We know that circumference; C of the circle with radius r is equal to`2pir`.

We have given difference between circumference and radius of the circle that is 37 cm.

`∴ C-r=2pir-r`

`∴(2pi-1)r=37`

Substituting `pi=22/7 ` we get,

`∴ (2xx22/7-1)r=37`

`∴ ((44-7)/7)r=37`

`∴(37/7)r=37`

Dividing both sides of the equation by 7/37, we get,  `∴r=7`

Therefore, circumference of the circle will be

\[2\pi r = 2 \times \frac{22}{7} \times 7\]

\[ = 44 {cm}^2\]

Hence, the correct choice is (b).