Question

The length in isometric drawing of line is 20 cm. What is the true length of it?

(a) 24.53 cm

(b) 15.46 cm

(c) 19.31 cm

(d) 23.09 cm

This question was posed to me in semester exam.

This is a very interesting question from Isometric Axes, Lines and Planes topic in division Isometric Projection of Engineering Drawing

Answer 1

The correct choice is (a) 24.53 cm

For explanation: The ratio of isometric length to true length is 0.815 so here it is given isometric length of 20 cm. 0.815 = 20 cm / true length => true length = 20 cm /0.815 =  24.53 cm. Every time the true length is more than isometric length.