Question

The line formed by intersection of principal planes is called _____________

(a) projection line

(b) origin line

(c) line of intersection

(d) reference line

I had been asked this question in unit test.

I need to ask this question from Planes of Projections and Four Quadrants topic in section Loci of Points & Orthographic Projections of Engineering Drawing

Answer 1

The correct answer is (d) reference line

Easiest explanation: The line formed by an intersection of principal planes or reference planes of projection that is the vertical plane or frontal plane and horizontal plane is called reference line which is denoted by the letters xy.