Crust

The edge grows more slowly than the middle.

A nine-inch pie has about twenty-eight inches of edge. That is nine times π.

Bake one twice as wide and it gets twice the edge, but four times the filling. The edge grows with the width. The middle grows with the width times itself.

So a small pie has more edge for its size than a large one. The ratio is not a matter of taste. It is a matter of radius.

A 9-inch pie: 31% of it lies within ¾ inch of the edge. Edge 28.3 in; filling 63.6 square in.

Figure Every pie drawn the same size, with its outer ¾ inch shaded. The shaded share shrinks as the real pie grows.

“Crust.” Wondering About Pi, no. 3.14159 (24 September 2026). wap.mom/crust/