The length of a rope, by which a calf is tied, is decreased from 9 m to 5 m. Find the decrease in the area that can be grazed by the calf.[Use $$\pi=\frac{22}{7}$$]

The length of a rope, by which a calf is tied, is decreased from 9 m to 5 m.

length of a rope initially =  9 m

length of a rope after decreased = 5 m

Decrease in the area that can be grazed by the calf = $$\pi\times[(length\ of\ a\ rope\ initially)^2-(length\ of\ a\ rope\ after\ decreased)^2]$$

= $$\frac{22}{7}\times[(9)^2-(5)^2]$$

= $$\frac{22}{7}\times[81-25]$$

= $$\frac{22}{7}\times56$$

= $$22\times8$$

= 176 $$m^{2}$$