Problem-5
Problem   Draw the top and front views of a rectangular pyramid of sides of base 40x 50 mm and height 70 mm when it lies on one of its larger triangular faces on HP.  The longer edge of the base of the triangular face lying on HP is inclined at 60⁰ to VP in the top view with the apex of the pyramid  being nearer to VP.

Solution :
The solution the problem is shown in figure 5. The projectors are obtained in 3-steps as illustrated in the figure.  In the first step, the solid is projected in the simple position with base BC perpendicular to VP. In the second step, the solid is tilted about the edge BC such that the face BCO is made to lie on the ground. The front view is rotated and the top view is projected from the front view and the top view in the first step. In step-3, the top view is rotated such that edge BC is inclined at 60° to XY line . The Front view is projected using this top view and Front view of Step-2.

 

Figure 5. The projections of the rectangular pyramid  of problem-5.