Necessary Views
The purpose of an orthographic drawing of a solid object is to completely describe the object in a minimum number of views. The number of essential views depends upon the intricacy of the object; complicated designs may requie several views in order to show complete detail.

When drawing an object, use only those views necessary for showing the shape of each detail of the object. The Top, Front, Right Side, Left Side, Bottom, and Back are called the Principal Views.