Figure 7.11 Profile lines
Line 1-2 is true length in the profile view and appears
foreshortened in the other two principal views. Dimensions D1
and D2 locate the end points of the line from the F/P fold line
and the H/F fold line. These measurements represent the
distance of point 1 and point 2 behind the frontal plane. The
angle that the profile line 1p-2p makes with the F/P fold line is
the angle between the line and the frontal plane (angle
F).Angle H is the angle that line 1p-2p makes with the
horizontal plane.