求二面角大小问题的“题眼”──选择好作平面角的一个点５５６０００贵州省黔东南民族师范高等专科学校罗时健求二面角的大小，就是求它的平面角的大小．而求平面角的大小，一般包含三个环节；首先须在二面均上作出它的平面角，然后寻求一个以此平面角为内角的三角形，最... Seeking the dilemma size problem of the “title eye” - choose a good point for the plane angle 556000 Guizhou Southeast Guizhou Normal University for Nationalities Luo Shijian seek the size of the dihedral angle, is to find the size of its plane angle. The size of the plane angle, generally contains three links; first must be made on both sides of its plane angle, and then seek a triangle with this plane angle for the inner angle, the most...