The barrel, then, is a cylinder having h equal to diameter or twice the radius. Since the volume of a cylinder is , the volume of this cylinder is .

What do you mean by "its size is a half circle"? What is itsThe second is a long swimming pool and I need to calculate the volume of the water in the pool, although my drawing skills aren't the greatest, I try my best, so: the pool is 4,8 metres long, it's the size of a half circle and it's radius (r) is 0,18m and diameter is 0,36m. So I need to calculate a segment of the circle first but I don't know how to do that, so please help me?shape? If a half circle, what measurement of the circle is its length od 4,8 m.?

fThank you in advance, and this time I read the description twice so I didn't miss anything relevant And also a 7 hour deadline on this :X

EDIT: The asnwers are as following: Problem one's measurements are 6,8m x 6,8m and the pool's volume is 96 liters, I just need to know how to get those results..