Question

If α,β,r are direction angles of a line and a = 60°, B = 45° then r =
(a) 30° or 90° (b) 45° or 60° (c) 90° or 30° (d) 60° or 120°​

Answer 1

Answer:

Line is always 180°

a+b+r=180°

60+45+r=180

105+r=180

r=180-105

r=75°