Current location - Training Enrollment Network - Mathematics courses - In the solid geometry of college entrance examination mathematics, can we directly set a real number without saying the side length?
In the solid geometry of college entrance examination mathematics, can we directly set a real number without saying the side length?
This should be analyzed in detail. When encountering problems such as cubes, equilateral triangles and squares. You can set a specific real value for the side length and calculate it, but it cannot be used for other problems.

For example, in the cube ABCD-a 1 b1d1,find the angle formed by dihedral angle A-B 1C 1-D, and let the side length be1.