The Best Way to Serve 20 Pies

We usually think of pies as circles. But these fine folks baked a “pie-cosahedron” — that is, an icosahedron, or 20-sided shape, made of pie! They cut and bent their own triangle-shaped metal pie tins. Then they made pecan pie, changing the recipe to be less gooey so pies wouldn’t fall apart. After baking the 20 triangle pies, they used magnets to hold all the tins in this shape. The question is, how many people does this geo-dessert feed?

Wee ones: If your pecan pie recipe uses flour, sugar, butter, pecans and a pinch of salt, how many ingredients does it use?

Little kids: How many triangles come together at each vertex (corner) of the icosahedron?  Bonus: If you eat 1 pie from this 20-sided shape all by yourself, how many are left?

Big kids: Which will serve more people, 9 of those pies cut into 5 slices each, or 8 of those pies cut into 6 slices each?  Bonus: If every pie has 3 sides, but every edge of the icosahedron (line between triangles) is shared by 2 pies…how many edges does the shape have?

Wee ones: 5 ingredients.

Little kids: 5 triangles.  Bonus: 19 pies left.

Big kids: The 8 pies cut into 6 apiece. That gives you 48 slices, while the 9 pies give you just 45. Bonus: 30 edges. The 20 faces have 60 sides all together when they’re laid flat and not touching…then when brought together, every pair of sides makes just 1 edge in the final dessert.

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