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
