Find the area of the following figure, in square cm, correct to one place of decimal. (Take π = 22/7).
Let the area of square ABCD be A.
It s given that, $\mathrm{AB}=10 \mathrm{~cm}$
So, $A=10 \times 10 \mathrm{~cm}^{2}$
It is given that a semicircle is attached to one side of the square.
The diameter of semicircle $=10 \mathrm{~cm}$
So, radius $r$ of semicircle $=5 \mathrm{~cm}$
We know that the area of semicircle of radius r is
$A^{\prime}=\frac{1}{2} \times \frac{22}{7} \times 5 \times 5$
Substituting the value of r,
$A^{\prime}=\frac{1}{2} \times \frac{22}{7} \times 5 \times 5$
$=39.3 \mathrm{~cm}^{2}$
From the above figure it is seen that a right angle triangle is cutoff from one side of square.
The area of right angle triangle $=\frac{1}{2} b h$
$=\frac{1}{2} \times 8 \times 6$
$=24 \mathrm{~cm}^{2}$
Now, the area $A^{*}$ of above figure is,
$A^{n}=$ Area of square $+$ Area of semicircle-Area of triangle
$=100+39.3-24$
$=115.3 \mathrm{~cm}^{2}$
Hence area of given figure is $115.3 \mathrm{~cm}^{2}$