Example of Alteration of Position and Reference Line Method:

Sketch the projections of a pentagonal prism edge of the base 50 millimeter long and height 90 millimeter, the axis of that is inclined at 70^o along with HP and parallel to the VP along with an edge of the base in HP.

 Solution

(a)   Sketch the projection of the solid assuming such the axis is perpendicular to the HP and parallel to VP along with one of the edge of the base (a, b) perpendicular to VP. Diagram (i) displays the views in this condition.

(b) Repeat sketching the elevation that like its axis creates an angle θ = 70^o along with the xy.

(c) By project the plan (ii) from projecting various points from initial plan (i) and inclined elevation.

(d)  Diagram (ii) displays the desired elevations and plan via alteration of position method.

(e)  Diagram (iii) displays the desired plan via alteration of reference line method.