We know that the perimeter of a cylinder is 2πr we will find it as we do always. The perimeter will be :
2 pi r
= 2 pi * 20
= 40 pi
Because it says rounded to the nearest tenth the answer will be : 125.6 cm^3
Because we have a half of a cylinder we will just divide the answer we got by 2:
125.6cm^3 /2 =62.8
The answer is 62.8 cm^3
