Name: Perimeter of a Closed Semicircular Figure
Uploaded: 2019-07-19
Duration: 2 min 24 s
Description: We know how to calculate the circumference or perimeter of a circle. Let’s watch how to calculate the perimeter of a closed semicircular figure in this video.

Question

The radius of a circular cricket ground is

76 m

. A drainage

2 m

wide has to be constructed around the cricket ground for the purpose of draining the rain water. Find the cost of constructing the drainage at the rate of

₹ 180

per square metre.

Accepted Answer

The radius of the inner circle (cricket ground), $r = 76 m$

A drainage is constructed around the cricket ground.

Therefore, the radius of the outer circle, $R = 76 + 2 = 78 m$

We have, area of the circular path $= π (R^{2} - r^{2})$

$= \frac{22}{7} \times (78^{2} - 76^{2})$

$= \frac{22}{7} \times (6084 - 5776)$

$= \frac{22}{7} \times 308$

$= 22 \times 44$

$= 968 m^{2}$

Given, the cost of constructing the drainage per square metre is $= ₹ 180$

Therefore, the cost of constructing the total drainage $=$ Area of the circular path $\times$ Cost of constructing the drainage per square metre

$= 968 \times ₹ 180 = ₹ 1, 74, 240$

Hence, the cost of constructing the total drainage is $76 m$ .

The radius of a circular cricket ground is $76 m$ . A drainage $2 m$ wide has to be constructed around the cricket ground for the purpose of draining the rain water. Find the cost of constructing the drainage at the rate of $₹ 180$ per square metre.

Important Questions on Measurements

Learn and Prepare for any exam you want !

The radius of a circular cricket ground is 76 m. A drainage 2 m wide has to be constructed around the cricket ground for the purpose of draining the rain water. Find the cost of constructing the drainage at the rate of ₹180 per square metre.

Important Questions on Measurements

Learn and Prepare for any exam you want !

The radius of a circular cricket ground is $76 m$ . A drainage $2 m$ wide has to be constructed around the cricket ground for the purpose of draining the rain water. Find the cost of constructing the drainage at the rate of $₹ 180$ per square metre.