The two planes oblique views to be defined in the projected perpendicular to the plane of projection, so that the angle formed with the horizontal plane is in them in true scale.
Although the plan view is almost always a top view of the object, in this case it is sufficient to define an elevation and a side view. We choose the side view hidden lines produce less (may not need any)
Hidden lines are not necessarily be represented. If you do not provide relevant information is better not to use them. If you put a, should put all.
Represent the views of the object
For proper viewing of the piece from different viewpoints, it may be necessary, Chrome browsers, installing a extension.
The camera can be defined to be orthogonal projection or conical.