Projections of a Plane

PROJECTIONS OF A PLANE

In Chapter 11, it was shown that the projection of a point (ie, Front view and Top view) is also a point.

In Chapter 12, it was shown that the projection of a line may be a point (or) a straight line depending on the position of straight line. Also, length of line in front view and top view may be equal or lesser than the true length, depending on the position of line.

In this chapter, it will be shown that the projection of a plane Figure may be a straight line (or) a plane figure depending on its position in quadrant angle. Also, the shape of plane figure in topview and front view may have either same shape or reduced size and shape depending on its position. 

If a lamina is parallel to any plane, the projection of lamina on that plane is also a plane figure having true shape and size (Fig. 13.4 (i) ).

If a lamina is inclined to any plane then the projection of lamina on that plane is also a plane figure but having reduced size and different shape. (Fig. 13.4 (ii))

But if a lamina is perpendicular to any plane then the projection of lamina on that plane is a straight line (Fig. 13.4 (iii))