We ordered ‘Mellow Mushroom‘ pizzas for supper last night and we still have about one pie left over in the frig, just waiting to be finished off.

Now: What is pizza? one way to say it is to assume the thickness of the pie is the value 'a' and the radius of the pie is the value 'z' then to say, “What is Pizza?” could be to ask, “What is the volume of a pizza?”

Thinking of a pizza as a very thin cylinder of height 'h' and radius 'r' we get.

[1] V = \pi r^{2}h

Substituting 'a' for the height 'h' and 'z' for the radius 'r' we get:

[2] V = \pi z^{2}a

Next  recall that the greek letter \pi can be written in English as Pi we get:

[3] V = Pi z^{2}a

Finally expanding the z{2} to be z z we get:

[4] V = Pi z z a