Question

A line which is parallel to vertical plane and making an angle of 20 degrees with profile has a length of 5 cm from top view. What is its true length?

(a) 1.71 cm

(b) 14.61 cm

(c) 5.32 cm

(d) 4.69 cm

The question was asked in an interview for job.

The origin of the question is 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 answer is (b) 14.61 cm

The explanation is: True length of line parallel to vertical plane and making angle with profile 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 top view L= 5/sin (20).