Showing posts with label geometry. Show all posts
Showing posts with label geometry. Show all posts

Monday, February 2, 2015

Pizza Geometry

First, let me say at the outset that despite strong temptation, I will refrain from using any pi/pie puns in this post. In fact, nobody says “pizza pie” anymore anyway.

For a long time, I've realized that a large (e.g., 16”) pizza is actually qualitatively better than a small (e.g., 12”) inch one. However, I had failed to demonstrate this with mathematical rigor. I shall now correct this oversight.

The important point is that regardless of the pizza diameter, the crust is always about an inch wide. That means that a 12” pizza really has a covered area that's 10” in diameter, while a 16” pizza has a 14” covered area.

Some simple geometry based on the old formula, A = πr2, shows us that a small pizza has a total area of 113 in2, but a covered area of only 79.5 in2. In other words, it's about 30% plain crust.

A large pizza, on the other hand, has a total area of 201 in2, but a covered area of 154 in2. That means the uncovered crust is only 23% of the total.

Quod erat demonstrandum1



1Unless you don't eat the crust, in which case none of this matters.