Question

How to solve this with explanation

Answer 1

Answer:

(i) 110 cm

(ii) 2975 cm2

Step-by-step explanation:

Given :- Side of square field = 70 cm

Radius of semi-circle = 1 x side of square field

2

= 1 x 70

2

= 35 cm

(i) Perimeter of lawn = circumference of semi-circle

= π x radius

= 22 x 35

7

= 110 cm

(ii) Area of square field excluding the lawn = Area of square field - Area of lawn

= (side x side) - (π x r²)

2

= (70 x 70) - ( 22 x 35 x 35)

7 x 2

= 4900 - 1925

= 2975 cm²

Answer 2

Solution -

i)

Given, Side of a square = 70 m.

From the given figure.

Diameter of semi-circle = 70 m.

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

Redius of lawn = 35 m.

Hence, perimeter of the lawn

= Diameter + Semiperimiter of Circle.

$70 + \frac{1}{2} \times 2\pi \: r \: = 70 + \frac{22}{7} \times 70 = 70 + 220 = 290m$

The Answer Is 290 m.

ii)

Area Of Square = 70 × 70 = 4900 m²

Hence, required area

Area Of Square - Area of Semicircle

$4900 - \frac{1}{2} \times \pi \times r²$

$4900 - \frac{1}{2} \times \frac{22}{7} \times (35)²$

• 4900 - 1925
• 2975 m²

The Answer Is 2975 m²

Hope It's Helpful