Question

A line of length 20 cm lies on profile plane whose ends are at a distance of 5 cm and 7 cm to horizontal plane. What is the length in top view?

(a) 7

(b) 14.8

(c) 15

(d) 2

I have been asked this question in homework.

The above asked question is from Projection of Line Contained by Plane in portion Projection of Lines of Engineering Drawing

Answer 1

Right choice is (b) 14.8

For explanation: Given the line is of length 20 cm present on profile plane and ends are at 5 and 7 cm away from horizontal plane at right angles. As we imagine the projection planes we can get the top view and distance relation as given here.  √(20^2-(7-5)^2 )= 14.8 cm.