Question

what is the perimeter of semicircle with a radius of 42 cm.

Answer 1

Perimeter of circle = $2 \pi r$
Perimeter of semicircle = $\pi r$
= (22/7)*42(where pi = 22/7)
= 22*6
= 132cm

Answer 2

formulae for perimeter of semi circle $\pi r+2r$=pi(42)+2(42)=42pi+44=42*22/7+44=216
216 is the answer.