What is the difference between 1st angle and 3rd angle projection?

Question

Accepted Answer

1st angle and 3rd angle projection are two methods of representing a 3D object on a 2D surface.

In 1st angle projection, the object is placed in front of the viewing plane and the views are taken from behind the object.
In 3rd angle projection, the object is placed behind the viewing plane and the views are taken from in front of the object.
1st angle projection is commonly used in Europe and Asia, while 3rd angle projection is commonly used in North America.
The symbol for 1st angle projection is a square with a dot in the center, while the symbol for 3rd angle projection is a square with three dots in a triangular formation.
Understanding the difference between the two is important for interpreting engineering drawings and blueprints.

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