Textbook of Engineering Drawing, Second Edition

------___ Orthographic Projections 5.21

2. Plane perpendicular to both H.P and v.P.

When a plane is perpendicular to both H.P. and V.P, the projections of the plane appear as straight
lines. Figure 5.25 shows the projections of a rectangular plane ABCD, when one of its longer edges
is parallel to H.P. Here, the lengths of the front and top views are equal to the true lengths of the
edges.

Fig. 5.25

c',d'

b' , ,a

x y

d,a

c,b

3. Plane inclined to one of the principal planes and perpendicular to the other

When a plane is inclined to one plane and perpendicular to the other, the projections are obtained in

two stages.

Problem:

(i) Projections of a pentagonal plane ABCDE, inclined at ~ to H.P and perpendicular to v.p and

resting on one of its edges on H.P.

Constructon : (Fig.5.26)

c'

Fig. 5.26