文[1]、文[2]、文[3]分别给出以下3个定理:定理1在存在内切球的前提下,多面体的体积均等于其表面积与相应内切球半径乘积的三分之一.定理2在存在内切球的前提下,圆柱、圆锥、圆台、球中的任何一个几何体的体积均等于其表面积与相应内切球半径乘积的三分之一.定理3“锥-锥”、“ The following three theorems are given in [1], [2], and [3] respectively: Theorem 1 The volume of a polyhedron is equal to the product of its surface area and the corresponding inscribed sphere radius on the premise that there is an inscribed sphere. One of the theorem. Theorem 2 In the presence of an inscribed sphere, the volume of any geometric body in a cylinder, a cone, a truncated cone, or a sphere is equal to one third of the product of its surface area and the radius of the corresponding inscribed sphere. Theorem 3 “Cone- Cone,"