Third Angle Projection.
This is obviously a cut and paste from somewhere. I suggest you try to put together an explaination that makes more sense.
Third angle projection is the drawing of an object by projecting (tracing) the object to a plane of projection infront of the object. Thus, the Plane of Projection is in between the Observer and the object (in simple words, the Object is behind the plane of projection .Any object has three dimensions, viz., length width and thickness. A projection is defined as a representation of an object on a two dimensional plane. In first angle projection, the object is imagined to be positioned in the first quadrant. In this case the object will be between the observer and the plane of projection . In third angle projection, the object is imagine to be positioned in the third quadrant. In this case the plane of projection is between the object and the observer.
Compard to the first angle projection the third angle projection has a transparentcy, while the first angle does not have any transparentcy.