Question

The true length of line is 40 cm and isometric view of it is drawn the length would decrease to ______

(a) 28.28 cm

(b) 32.6 cm

(c) 34.6 c

(d) 38.63 cm

This question was posed to me by my college professor while I was bunking the class.

This key question is from Isometric Axes, Lines and Planes in chapter Isometric Projection of Engineering Drawing

Answer 1

Right option is (b) 32.6 cm

The best explanation: The ratio of isometric length to true length is 0.815 so here it is given true length of 40 cm. 0.815 = isometric length / 40 cm => isometric length = 40 cm x 0.815 = 32.6 cm. Every time the true length is more than isometric length.