Question

Find the area of Fig. 20.25, in square cm, correct to one place of decimal. (Take π = 22/7)

Answer 1

The given figure is:

Construction : Connect A to D.
Then, we have: Area of the given figure = (Area of rectangle ABCD + Area of the semicircle) - (Area of ∆ AED).
∴ Total area of the figure = (Area of rectangle with sides 10 cm and 10 cm) + (Area of semicircle with radius\[ = \frac{10}{2} = 5 cm)\] - (Area of triangle AED with base 6 cm and height 8 cm)
\[ = (10 \times 10) + (\frac{1}{2} \times \frac{22}{7} \times 5^2 ) - (\frac{1}{2} \times 6 \times 8)\]
\[ = 100 + 39 . 3 - 24\]
\[ = 115 . 3 {cm}^2\]