Question

In Fig. arcs have been drawn of radius $21cm$ each with vertices $A,B,C$ and $D$ of the square $ABCD$ as centres. The area of the shaded region is

• A. $693$ $c{m}^2$
• B. $346.5$ $c{m}^2$
• C. $2772$ $c{m}^2$
• D. $1386$ $c{m}^2$

Answer 1

The correct option is D $1386$ $c{m}^2$

Area of each sector is equal.

Area of shaded region $=4\times \frac{{90}^0}{{360}^0}\pi \left({21}^2\right)$

$=\frac{22}{7}\times {21}^2$

$=1386{cm}^2$