Question

A line which is parallel to vertical plane and making an angle of 50 degrees with horizontal plane has a length of 5 cm from side view. What is its true length?

(a) 3.2 cm

(b) 3.8 cm

(c) 7.77 cm

(d) 6.52 cm

This question was addressed to me in an online quiz.

I'm obligated to ask this question of True Length of a Straight Line and its Inclinations with the Reference Planes in chapter Projection of Lines of Engineering Drawing

Answer 1

The correct choice is (c) 7.77 cm

To explain: True length of line parallel to vertical plane and making angle with horizontal plane can be of two values either from top view or side view but from front view the length will be given length. As here it is given side view L= 5/cos (50).