Can someone explain the steps to finding the perimeter of a semi-circle? I didn't really understand it during class. Thanks

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

pretty sure its b

step-by-step explanation:

why? because i noticed a pattern. 60 120. those numbers without the zero, make the 6 times tables leaving your answer to be b since 6 times 4 is 24 and adding a zero making it 240.