Question

The length of line placed in profile plane and making an angle of 155 degrees with the horizontal is 3 cm from top view. What is the actual length?

(a) 3.31 cm

(b) 7.09 cm

(c) 1.26 cm

(d) 2.7 cm

The question was posed to me in an interview.

I want to ask this question from Line contained by a Plane Perpendicular to Both the Reference Planes topic in portion Projection of Lines of Engineering Drawing

Answer 1

Correct answer is (a) 3.31 cm

To explain: The line is making 155 degrees is equal to the line making 25 degrees as 180-155 =25. The length of line from top view will be cosine of actual length. L * cosine (25) =3 cm, L= 3/ cosine (25)= 3.31 cm.