3. A quadrangular regular pyramid has equilateral triangles of side 2 cm for lateral faces. Calculate a) the surface area of the pyramid. b) the angle between a lateral edge the base plane. c) the angle formed by two opposite lateral edges. d)the dihedral angle formed by a lateral face and the plane. e) the dihedral angle formed by two adjacent lateral faces

liz041    2   05.05.2020 09:59    1