Question

Question 80 (i)

Rani bought a new field that is next to one she already owns in the given figure. This field is in the shape of a square of side 70 m. She makes a semi-circular lawn of maximum area in this field.

Find the area of the square field excluding the lawn.

Answer 1

Given, side of a square = 70 m

From the given figure, the diameter of semi-circle is same as the side of a square.
$\therefore$ Diameter of semi-circle = 70 m
$\because$ Dimeter of semi-circle = Side of square
$\therefore Radius=\frac{70}{2}=35m[\because radius=\frac{diameter}{2}]$
$\therefore$ Perimeter of lawn $=\pi r+2r=\frac{22}{7}\times 35+2\times 35=110+70=180m$