Answer:
cubic feet
Step-by-step explanation:
We know that
The inside tubing radius is 2 inches.
The task is to establish the volume expression for L feet of drainage tubing in cubic feet.
Tube length equals L feet.
1 foot = 12 inches
feet
Given that the formula for the volume of a cylinder is 
Where r is the cylinder's radius
h is the cylinder's height.
By substituting the respective values into the formula, we obtain:
Volume of drainage tubing = 
Volume of drainage tubing =
cubic feet
This is the needed expression for the volume of L feet of drainage tubing.