Question

A path 2 m wide surround a circular pond of diameter 40 m. How many cubic meters of gravel are required to grave the path to a depth of 20 cm?

Answer 1

We have,

Diameter of circular pond $=40mtr.$

Then, the radius of circular pond $=20mtr.$

Depth of pond $=20cm.$or $0.20mtr.$

So,

The area of path

$=\pi {(20+2)}^2-\pi {\left(20\right)}^2$

$=264m^2$

Amount of gravel needed

$=Area\times Depth$

$=264m^2\times 0.20m$

$=52.8m^3$

Hence, this is the answer.