Question

A line which is parallel to horizontal plane is made to turn to an angle of 35 degrees with vertical and then turned to an angle of 45 degrees with horizontal plane and now the line has a length of 8.5cm from top view. What is its true length?

(a) 7.37 cm

(b) 12.02 cm

(c) 10.9 cm

(d) 6.01 cm

The question was posed to me during an interview.

Question is from True Length of a Straight Line and its Inclinations with the Reference Planes topic in chapter Projection of Lines of Engineering Drawing

Answer 1

Right option is (b) 12.02 cm

To explain I would say: True length of a line parallel to horizontal plane and making angle with respect to horizontal 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= 8.5/cos(45).