why is it called third angle projection
So far we have only covered one method of Orthographic Projection, this is known as First Angle Projection. First Angle Projection is used in Europe and most of the world. However America and Australia use a method known as Third Angle Projection.In First Angle Projection we place our object in the First Quadrant (see above figure). This means that the Vertical Plane is behind the object and the Horizontal Plane is underneath the object.In Third Angle Projection the Object is placed in the Third Quadrant.This means that the Vertical Plane is in front of the object and the Horizontal Plane is above the object. To see the effects of this watch the animation below.irst Angle Projection is used in Europe and most of the world. However America and Australia use a method known as Third Angle Projection. In First Angle Projection we place our object in the First Quadrant (see above figure).
As you know, one is called First Angle, the other is called Third Angle. They differ only in the position of the plan, front and side views on the page. This is an example of First Angle Projection.This is used mainly in Europe. First Angle Projection Third Angle Projection.Used mainly in the US.s you know, one is called First Angle, the other is called Third Angle. They differ only in the position of the plan, front and side views on the page. This is an example of First Angle Projection.