Question

If a line is in profile plane making an angle of 30 degrees with vertical plane. In which angle the line makes with the horizontal plane?

(a) Can’t say

(b) 90 degrees

(c) 0 degrees

(d) 60 degrees

I have been asked this question in exam.

I'd like to ask this question from Line contained by a Plane Perpendicular to Both the Reference Planes topic in section Projection of Lines of Engineering Drawing

Answer 1

The correct choice is (d) 60 degrees

The explanation: If a line placed within the plane the angles made by the line with other perpendicular planes will be complimentary that means their sum will be equal to 90 degrees.90 degrees- 30 degrees = 60 degrees.