Question

If the perimeter of a semi-circular park is 72m , find its area and radius

Answer 1

Hi ,

Let radius of the semi circle = r m

Perimeter of the semicircle = πr + 2r

P = r ( π + 2 )

= r ( 22/7 + 2 )

= r /7 ( 22 + 14 )

= 36r/7 ----( 1 )

P = 72 m ( given ) ---( 2 )

( 1 ) = ( 2 )

36r/7 = 72

r = ( 72 × 7 ) / 36

r = 2 × 7

r = 14 m

Area = πr²/2

= ( 22/7 ) × 14² × 1/2

= ( 22 × 14 × 14 ) / ( 7 × 2 )

= 22 × 14

= 308 m²

I hope this helps you.

: )