Module 2 : Theory of projections

Lecture 25 : Examples on projections of planes

 

Problem 2. Draw the front view, top view and side view of a square lamina. The surface of the lamina is inclined at θ to HP and perpendicular to VP.  

Solution.  The thre views of the square lamina is shown in figure 2. Since the lamina is perpendicular to VP, its front view will be a line [a’(b’) c’ (d’)] having length as the true length of the edge of the square and inclined at θ to XY line. The corners B and C coincide with A and D in the front view. Since the lamina is inclined to HP at θ, it is also inclined to the left PP at (90- θ). The square lamina is projected on to VP, HP and left PP.   Draw  vertical projectors from points a’, b’, c’ and d’.  On any position on these lines construct the rectangle a-b-c-d  such that length ab  and cd are equal to the true length of the square edge. The rectangle a-b-c-d is the top view of the lamina.  The side view of the lamina a”,b”,c” and d” can be obtained by drawing projectors from points a’,b’,c’and d’ and a, b, c, and d.

Figure 2. The projection sof the square lamina as mentioned in problem 2.