Answer:
First, let's work out the V of container A and B
V_A = pi x (diameter/2)^2 x height = pi x (26/2)^2 x 14 = 2366 pi (ft3)
V_B = pi x (diameter/2)^2 x height = pi x (18/2)^2 x 15 = 1215 pi (ft3)
After pumping water from container A to container B until B is full:
The empty space inside container A would be:
V_empty = V_A - V_B = 2366 pi (ft3) - 1215 pi (ft3) = 1151 pi (ft3) = ~3615.97 (ft3)
Area of the triangle = (1/2)*base*height
base = x
height = altitude = x+6
Area of the triangle = (1/2)*x*(x+6) = 108
(1/2)*x*(x+6) = 108
x²+6x-216 =0
(x+18)(x-12)=0
x=-18, or x=12
We can use only positive value, so x=12.
Base =12 cm.
