Why Triangles Are Easy and Tetrahedra Are Hard

Do you think there’s a triangle whose angles measure 41, 76 and 63 degrees? At first, answering this may seem easy. From geometry class we know that the sum of the measures of the interior angles of a triangle is 180 degrees, and since 41 + 76 + 63 = 180, the answer must be yes. But there’s more to this question than meets the eye. The triangle angle sum theorem tells us that, given a triangle in…

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