Question

How many cubic feet of concrete are needed to pour 4 cylindrical pillars 5 feet high with a diameter of 4 inches?

Answer 1

Answer:  1.75 cubic feet concrete is needed.

Step-by-step explanation:

Alright, lets get started.

The volume of the pillar is : $\pi r^2h$

We have given the height is 5 feet.

We have given the diameter is 4 inches.

So the radius will be : $\frac{4}{2}=2 \ inches$

Converting inches into feet.

The radius will be : $\frac{2}{12} \ feet$ $= 0.167 feet$

So the volume of the cylinder will be : $\pi * 0.167^2*5$

So the volume of the cylinder will be : $0.4380 \ cubic \ feet$

As there are 4 pillars, so total volume will be : $4*0.4380$

So, total volume will be : $1.75 \ cubic \ feet$

Hence 1.75 cubic feet concrete is needed.   :   Answer

Hope it will help :)