Question

A line AB, 90 mm long is inclined at 30° to HP and parallel to VP.  The line is 80 mm in front of VP. The lower end A is 30 mm above HP. The upper end B is 50 mm in front of the right PP. The right profile plane will show a _________ projection.

(a) point

(b) small

(c) true

(d) false

This question was posed to me in quiz.

Enquiry is from Projection of Straight Lines topic in chapter Orthographic Projection, Projections of Lines, Planes and Solids of Civil Engineering Drawing

Answer 1

Right answer is (d) false

Easiest explanation: The projections of line AB shown in figure 5 can be obtained in the following manner. Mark a’, the front view of the end A, 30 mm above HP. Draw the front view a΄b΄ = 90 mm inclined at 30° to XY line.

Project the top view ab parallel to XY line. The top view is 80 mm in front of VP. Draw the X1Y1 line at a distance of 50 mm from b’.  Draw a 45° line through O. Draw the horizontal projector through the top view ab to cut the 45 ° line at m.  Draw a vertical projector through m.  Draw the horizontal projectors through a’ and b’ to intersect the vertical projector drawn through m at a” and b”.  Connect a΄΄ b΄΄ which is the left side view.