Question

When a line is parallel to one plane and inclined to the other, the projection of the line on the plane to which it is parallel will show its __________ length.

(a) shortened

(b) true

(c) enlarged

(d) false

I got this question during an interview.

This interesting question is from Projection of Straight Lines topic in portion Orthographic Projection, Projections of Lines, Planes and Solids of Civil Engineering Drawing

Answer 1

The correct choice is (b) true

The best I can explain: The projected length on the plane to which it is inclined will always be shorter than the true length.  In figure 2, the line AB is parallel to VP and is inclined to HP. The angle of inclination of AB with HP is being θ degrees.  Projection of line AB on VP is a’b’ and is the true length of AB.  The projection of line AB on HP is indicated as line ab. Length ab is shorter than the true length AB of the line. Refer the figure below.