Question

Find the area and perimeter of the following semi-circle :

Diameter= 7 cm

Answer 1

Diameter= 2r 

`=> "r" = "diameter"/2 = 7/2` = 3.5 cm

Area of the semi-circle = `1/2 pi "r"^2`

`= 1/2 xx 22/7 xx 3.5 xx 3.5`

= 19.25 cm²

Perimeter of the semi-circle = (πr + 2r) 

`= (22/7 xx 3.5) + (2 xx 3.5)`

= 18 cm

Therefore, Area= 19.25 cm² and Perimeter= 18 cm