Area: size of a pizza
As a math tutor, you notice these little surprises about everyday things.
We all know that, with a circle,
Years ago, I worked in a pizza place. A small was 10″ (diameter), while a large was 14″. Let’s compare the sizes.
First, we’ll agree that from an eating point of view, the size of a pizza is really its area, rather than its diameter.
For the small, the diameter being 10″, its radius is of course 5″. Its area is
A=Πr2=Π(5)2=Π(25)≈78.5 square inches
For the large, the diameter being 14″, its radius is 7″, so its area is
A=Πr2=Π(49)≈154 square inches
The ratio of the areas:
I think we can agree that 1.96≈2.
Therefore, the 14 inch pizza is really twice the size of the 10 inch. You can check what kind of deal you’re getting on the large:)
Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.