SOLUTION: A child's block is in the shape of half a cylinder. (It has a picture and it's like and the arc thing, it looks like a semicirle to me tho). The block is 10cm wide, 5 cm high and 3

Algebra ->  Surface-area -> SOLUTION: A child's block is in the shape of half a cylinder. (It has a picture and it's like and the arc thing, it looks like a semicirle to me tho). The block is 10cm wide, 5 cm high and 3      Log On


   

Question 955449: A child's block is in the shape of half a cylinder. (It has a picture and it's like and the arc thing, it looks like a semicirle to me tho). The block is 10cm wide, 5 cm high and 3.5 cm thick. Find the surface area. The answer is 35 + 42.5pi in. I don't get how to get to that answer. Thanks!
Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
For 2 half circles(top+bottom)A%5B1%5D=Area=%28pi%29r%5E2
... A%5B1%5D=%28pi%29%285%5E2cm%5E2%29=25%28pi%29cm%5E2
For curved side(1/2 circumference*height)A%5B2%5D=Area=%28pi%29r%2Ah
...A%5B2%5D=%28pi%29%285cm%29%283.5cm%29=17.5%28pi%29cm%5E2
...A%5B1%5D%2BA%5B2%5D=42.5%28pi%29cm%5E2
For flat side A%5B3%5D=Area=height%2Adiameter
...A%5B3%5D=%283.5cm%29%2810cm%29=35cm%5E2
Total surface area=42.5%28pi%29cm%5E2%2B35cm%5E2 I don't know where the inches came from.