Question

A horse is tied to a pole fixed at one corner of a square field having one side $30m$ by mean of a rope $14m$ long. Find the increase in the grazing area if the rope length is increased by $7m$.

Answer 1

REF. Image.

Grazing area when

r = 14 $\Rightarrow Area=\frac{1}{4}\times \pi (14{)}^2$

Area when r = 21 m

$A_2=\frac{1}{4}\pi (21{)}^2$

$A_1=49\pi$ $A_2=110.25\pi$

% income $=\frac{A_2-A_1}{A_1}\times 100$

$=\frac{61.25\pi }{49\pi }\times 100$

= 125 %