Feb 27, 2014
Planet Money wrote about the economics of pizza size, but I feel like they left out the actual math. It's not complicated, but basically since
Simplifying the formula, you can write that the change in area is related to the change in diameter as follows:
area = π*radius2 = (π/4)*diameter2, the area changes with the square of the diameter. So for an 8-inch pizza, the area is 50 square inches, while the area of a 12-inch pizza is 113 square inches. A 50% increase in diameter equates to a 125% increase in area. That's the power of exponents. Simplifying the formula, you can write that the change in area is related to the change in diameter as follows:
Δa = ((π/4) * d22 - (π/4) * d12) / ((π/4) * d12)
= (d22 / d12) - 1
Helpful for the next time you want to get a wedgie in a pizza place. #math
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