How Many Cubic Feet Of Concrete Do I Need To Fill A Hole 42inches Deep By 15 Inch Diameter ?

To find this, we need to find the volume of the hole.

Volume = base area x depth

Since the hole is circular, the formula for finding its area is:

Area = pi x radius²
radius = diameter/2
radius = 15/2
radius = 7.5 inches

Area = pi x radius²
Area = 3.14 x 7.5²
Area = 3.14 x 56.25
Area = 176.63 square inches

Volume = area x depth
Volume = 176.63 x 42
Volume = 7418.5 cubic inches

Thus, you need 7418.5 cubic inches of concrete to fill the hole.