I want to know the solutions with this different set of problems. Thank you in advance.

1. A line intersect three parallel planes and its segments between the planes are 10 dm and 15 dm.

Find the distances between the planes if the line forms an angle of 60° with a line othat is perpendicular to one of the planes.

2. If three parallel planes divide one line into segments of 12 m and 18 m, and the line makes an angle of 60° with the first plane, find the distance between the second and the third planes.

3. Between what limits must the third face angle of a trihedral angle lie if the other two face angles are to be 70° and 100°?

4. If two angles of a trihedral angle are 130° and 140°, find the lower limit which the third face angles approaches?

5. How many kinds of polyhedral angles can be formed whose face angles are each 30°? 45°? 90°?