Question

Four horses are tethered at $4$ corners of a square field of side $70$ meter so that they just cannot reach one another. The area left ungrazed by the horses is

• A. $1050sq.m$
• B. $3850sq.m$
• C. $950sq.m$
• D. $1075sq.m$

Answer 1

Answer: (A)

$1050sq.m$

Area ungrazed $=$ Total area - 4 $\times$ ar. grazed by each horse

$=70\times 70-4\times \frac{90}{{360}^0}\times \pi \times \frac{70}{2}\times \frac{70}{2}$

$=4900-\frac{22}{7}\times 35\times 35$

$=4900-3850$

$=1050m^2$