Question

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

Answer 1

Let the radius of the park be r.
Length of chain = Perimeter of the semicircular park

⇒ 108 = Length of the arc +Diameter

`=> 108 = 1/2xx2pi"r" + 2"r"`

`⇒ 108 = r (22/7+2) `

`=> 108 = 36/7"r"`

⇒ r = 21 m

Now, Area of park` = 1/2pi"r"^2 = 1/2xx22/7xx(21)^2 = 693   "m"^2`

Hence, the area of the park is 693 m² .