Question

The length of the projection of a line on a plane is 12 cm. If the length of the line is 18 cm, find the angle it makes with the plane?

Answer 1

α - the angle;
We will use C A H method:
cos α = 12 cm / 18 cm = 0.667
α = cos ^(-1) 0.667 = 48.19° ≈ 48° 11`
Answer:
The angle which a line makes with the plane is 48° 11 `