math
posted by michael .
A 16ft ladder is placed 4ft from the base of the building. How high on the building will the ladder reach?

4^2 + h^2 = 16^2
h^2 = 256  16 = 240 = 16*15
h = 4 sqrt 15
h = 15.5 
Sketch the graphs of f(x) = x^2 and g(x) = 2x. Find a number a between 0 and 2 so that when the region between the graphs of f and g for 0 <= x <= a is revolved about the yaxis, the volume of the solid produced is 7pia3/12 . Please show all work