Question

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

a)Perimeter of the lawn
b)Area of the square field
c)Area of the square field excluding the lawn.
d)Perimeter of the square field.5*5x

Answer 1

Answer:

Given, Side of a square =70m

From the given figure.

Diameter of semi-circle =70m

So, Side of square = Diameter of semi-circle =70m

So, radius of lawn=35m

Hence, perimeter of the lawn =diameter+semiperimeter of circle

=70+

2

1

×2πr=70+

7

22

×70=70+220=290m

(ii) Area of square =70×70=4900m

2

Hence, required area Area of square - area of semicircle

=4900−

2

1

×π×r

2

=4900−

2

1

×

7

22

×(35)

2

=4900−1925

=2975m

2

solution