MathDB

5

Part of 1994 National High School Mathematics League

Problems(1)

Pyramid Problem

Source: 1994 National High School Mathematics League, Exam One, Problem 5

3/1/2020
In regular nn-regular pyramid, the range value of dihedral angle of two adjacent sides is (A)(n−2nπ,π)(B)(n−1nπ,π)(C)(0,π2)(D)(n−2nπ,n−1nπ)\text{(A)}\left(\frac{n-2}{n}\pi,\pi\right)\qquad\text{(B)}\left(\frac{n-1}{n}\pi,\pi\right)\qquad\text{(C)}\left(0,\frac{\pi}{2}\right)\qquad\text{(D)}\left(\frac{n-2}{n}\pi,\frac{n-1}{n}\pi\right)
geometry3D geometrypyramid