Difference between First Angle Projection and Third Angle Projection

We use the orthographic projection technique to represent a 3D object on a 2D plane. The orthographic projection system makes use of parallel lines to transcribe 2D views of 3D objects.

What is a First Angle Projection?

According to the First Angle Projection schema, the item is seen as being in the first quadrant. The top of the horizontal plane and the front of the vertical plane are both acceptable placements for objects. The item is positioned between the projection planes and the viewer, or between the observer and projection planes the item is positioned. In first angle projection, the plane of projection is assumed to be solid.

What is a Third Angle Projection?

When using the Third Angle Projection schema, the item is shown as being in the third quadrant. An item can be positioned behind the vertical planes and at the bottom of the horizontal plane. In the US, third-angle projection is frequently utilized. When projecting from a third angle, the projection plane is considered to be transparent.

Difference between First Angle Projection and Third Angle Projection

Parameter	First Angle Projection	Third Angle Projection
Method of Projection	When a plane is divided into four quadrants, A first angle projection scheme allows for the placement of any item in the first quadrant.	When a plane is divided into four quadrants, In a third angle projection schema, any object may be placed in the third quadrant.
Placement of Objects	It positions the thing in front of the observer and the projection plane for a first-angle projection.	In order to project an image from a third angle, it positions the object between both the observer and the object.
State of Projection Plane	In the first projection angle, you can assume that the projection plane is opaque (solid).	In the third projection angle, you can assume that the projection plane is transparent.
Uses	Widely employed in Canada, Europe, and India.	widely used in both Australia and the US
Identification	A First Angle Projection picture (drawing) may be recognized by its first angle projection symbol. This angle of projection symbol is often located next to the Title block in the angle of projection block.	A Third Angle Projection picture (drawing) may be recognized by its third angle projection symbol. This angle of projection symbol is often located next to the Title block in the angle of projection block.