Question:
In the following figure, OABC is a square of side 7 cm. If OAPC is a quadrant of a circle with centre O, then find the area of the shaded region. (Use π = 22/7)
Solution:
Area of shaded region = Area of square OABC − Area of quadrant OAPC
$=(\text { Side })^{2}-\frac{1}{4} \pi r^{2}$
$=(7)^{2}-\frac{1}{4} \times \frac{22}{7} \times 7 \times 7$
$=49-38.5$
$=10.5 \mathrm{~cm}^{2}$
Hence, the area of the shaded region is $10.5 \mathrm{~cm}^{2}$