In figure c is top figure i.e. small triangle formed represents ?E? portion of object given in question, right figure attached to triangle represents ?F? portion of object given in question.

In visual ray method, points on perspective are obtained by project ting top view with eir front view or side view of visual rays. The method of drawing perspective by visual ray method is illustrated by problem below:
Problem
A hexagonal lamina of 45 mm edge lies on ground. The corner which is nearest to PPP is 25 mm behind it and an edge containing that corner is making 50° to PP. The station point is 50 mm in front of PPP. 60 mm above Ground plane and lines in a central plane which is 80 mm to left of corner nearest to PPP. Draw perspective view of lamina by visual ray method.
Solution: The solution to problem is illustrated in figure below:-

When human eye looks at a scene, objects in distance appear smaller than objects close by. Orthographic projection ignores this effect to allow creation of to-scale drawings for construction and engineering.
Orthographic projections are a small set of transforms often used to show profile, detail or precise measurements of a three dimensional object. Common names for orthographic projections include plane, cross-section, bird’s-eye, and elevation.

Line method: A number of lines are drawn on lateral surface of one of solids and in region of line of intersection. Points of intersection of se lines with surface of or solid are n located. These points will lie on required line of intersection. They are more easily located from view in which lateral surface of second solid appears edgewise (i.e. as a line). The curve drawn through se points will be line of intersection.
Cutting-plane method: The two solids are assumed to be cut by a series of cutting planes. The cutting planes may be vertical (i.e. perpendicular to H.P.), edgewise (i.e. perpendicular to V.P.) or oblique. The cutting planes are so selected as to cut surface of one of solids in straight lines and that of or in straight lines or circles.

Isometric axes can be positioned in a number of ways to create different views of same object. Figure 6( a ) is a regular isometric, in which viewpoint is looking down on top of object. In a regular isometric, axes at 30° to horizontal are drawn upward from horizontal. In reversed axis isometric, as shown in figure 6( b ), viewpoint is looking up on bottom of object, and 30° axes are drawn downward from horizontal. Figure 6( c ) & ( d ) show long axis isometric, where viewpoint is looking from right or from left of object, and one axis is drawn at 60 ° to horizontal. While drawing Isometric view, first view point will have to be decided for obtaining maximum technical information.

In this method sphere is cut into a number of horizontal zones, each of which may be taken as frustum of a cone whose apex is at extended chords. Now, develop each zone independently by radial line method. For example to develop zone A, as it is a frustum of a rigid circular cone with its apex o, on vertical axis of sphere. Apply radial-line method and obtain development of zone.

This is back view representation of any object. E represents back view.
The dotted circle represents that particular object is on or side of viewing plane.

The intersection curve of two polyhedrons is a polygon i.e. tori. The display of a parametrically defined surface is usually done by mapping a rectangular net into 3-space. The spatial quadrangles are nearly flat. So, for intersection of two parametrically defined surfaces, algorithm for intersection of two polyhedrons can be used.