最近笔者对正棱锥的有关角作了一点研究,得到几个结论,现论述如下,与读者共享.定理正n棱锥S-A_1A_2A_3…A_(n-1)A_n的侧面等腰三角形顶角为α,相邻两侧面所成二面角的平面角为α;侧棱与底面所成的角为θ,侧面与底面所成的角为φ,侧面等腰三角形的 Recently, I have made some research on the related angle of positive pyramid, and got several conclusions, which are discussed as follows and shared with the reader. The theorem is that the apex angle of the isosceles triangle of positive n-pyramid S-A_1A_2A_3 ... A_ (n-1) A_n is α , The adjacent two sides of the dihedral angle of the plane angle α; side edge and the bottom of the angle formed by θ, the angle between the side and the bottom surface is φ, the side isosceles triangle