How do you write one eighth pi times the cube of the diameter

So how do we write the given situation:

one eight pi times the cube of the diameter

=> one eight = 1/8

=> pi = 3.14

=> cube of diameter = d^3

Now, that we have the simplified equivalent of the given problem. Let’s start writing it into equation

=> 1/8pi (d^3)

You can now start solving with this given situation. Just change the pi with its original value which is 3.14