Question

Find the area in square cm, correct to one place of decimal. (Take $\pi =\frac{22}{7}$)

Answer 1

Area of rectangle ABCD = length $\times$ breadth
= 10$\times$ 10 = 100 cm$c{m}^2$

​Area of right triangle AED = $\frac{1}{2}\times$ base$\times$ height
= $\frac{1}{2}\times 6\times 8$ = 24 $c{m}^2$

Area of ABCDE = Area of ABCD - Area of right triangle AED
​= 100 - 24 = 76 $c{m}^2$

In semicircle BC ,
given d = 10 cm
r = 5 cm
​Area of semicircle BC = $\frac{\pi R^2}{2}$
= $22\times 5\times \frac{5}{7}\times 2$
= $25\times \frac{11}{7}$
= 39.2 $c{m}^2$

Area of the figure = Area of ABCDE + Area of semicircle BC
= 76 + 39.2 =115.2 $c{m}^2$