We are to solve for the value of the altitude of the given cylinder which has a radius of 5 feet and a lateral area of 70pi ft². To solve this we should recall that the formula in solving the lateral area of a cylinder is Lateral Area = 2pi*r*h. The solution is shown below:
r is equal to 5 ft
lateral area = 70pi
Solving for h, we have:
70pi = 2pi*5*h
70pi / 2pi = 5h
35 = 5h
divide both sides by 5, we have:
35/5 = 5h/5
7 = h
The answer for the length of the altitude is 7 feet.