What is the difference between the included angle between faces and the dihedral angle between faces in senior two mathematics? What kind of question is to answer two complementary angular sizes? Is to have two. 1 makes no difference.

2 "dihedral angle = = a straight line, plus two half planes, constitutes a thing called dihedral angle.

3 "Plane angle = = dihedral angle is called plane angle.

4 "Specific analysis of specific problems, find a plane angle, and his complementary angle is obvious.

I hope it helps you!