volume of a cylinder?

Question

The volume V of a cylinder is given by the formula V=3.14r^2h, where r is the radius of the cylinder and h is the hieght, A cylinder with the height of 10 feet have volume 140ft.^3. To the nearest tenth of a foot, what is the radius of the cylinder?

Answer 1

v = πr² h
r² = v / (πh)
r² = 140 / 10π
r = √ (14 / π)
r = 2.1 ft

Answer 2

if 3.14 x R^2 x H = 140 ft^3
Then, substituting values, we get

3.14 x R^2 x 10 = 140
=> R^2 = 140/ (10x3.14)
=> R^2 = 4.45
=> R = 2.11 feet
The radius of the cylinder = 2.11 feet.

Answer 3

2.111539 feet