Projection of Points on Auxiliary Planes

Projection on Auxiliary Vertical Plane

Point P is situated in the first quadrant at a height m above HP. An auxiliary vertical plane AVP is set up perpendicular to HP and inclined at Φ to VP. The point P is projected on VP, HP and AVP.
As shown in figure 3, p' is the projection on VP, p is the projection on HP and P₁' is the  projection on AVP.
Since point is at a height m above HP, both p' and p₁’ are at a height m above the XY and X₁Y₁ lines, respectively

Figure 3. Projection of Point P on VP, HP and AVP