Question

The length of a chain used as a boundary of a semicircular park is 108m. Find the area of the park.

Answer 1

Answer = 693

Explanation:
Semicircle boundary length = πr + 2r = 108
Therefore r = 21

Area of a Semicircle = π(r^2)/2
= π (21^2)/2
= 693

Answer 2

Answer:

The area of the park is 693 sq.m.                                        

Step-by-step explanation:

Perimeter of semicircle = $\pi r+2r$

We are given that The length of a chain used as a boundary of a semicircular park is 108m.

So, $\pi r+2r =108$

$\frac{22}{7}r+2r =108$

$\frac{22r+14r}{7} =108$

$\frac{36r}{7} =108$

$r =108 \times \frac{7}{36}$

$r =21$

Area of semicircle = $\frac{\pi r^2}{2}$

                                = $\frac{\frac{22}{7} \times  21^2}{2}$

                                = $693$

Hence the area of the park is 693 sq.m.