Question

A cow is tied at the corner of a square field with 21 m long rope. The side of the square is 25 m The area of the field on which the cow cannot graze is

• A. 441 $m^2$
• B. 346.5 $m^2$
• C. 100 $m^2$
• D. 278.5 $m^2$

Answer 1

Answer: (D)

278.5 $m^2$

The required area=area of the square field-area of the sector with radius r=21m and
$\theta ={90}^{\circ }$
$=(25\times 25-\frac{\frac{22}{7}\times 21\times 21}{360}\times 90)m^2$
$=(625-\frac{22\times 3\times 21}{4})m^2$
$=(625-346.5)m^2$
$=278.5m^2$