Answer with Step-by-step explanation:
The perimeter(P) of a semi circle is given by:
P=πr+2r
where r is the radius of the semicircle
r=d/2 where d is the diameter
We are given diameter=12 cm
⇒ Radius= 12/2
= 6 cm
Perimeter=3.14×6+2×6
=18.84+12
=30.84 cm
Hence, best approximation for the perimeter of a semicircle with a diameter of 12 cm is:
30.84 cm