Difference betweenfirst angle and third angle projection.

Question

Accepted Answer

First angle and third angle projection are two different methods used in engineering drawings to represent a 3D object on a 2D plane.

First angle projection is commonly used in Europe and Asia, while third angle projection is commonly used in North America.
In first angle projection, the object is placed in the first quadrant and the views are projected onto the planes surrounding the object.
In third angle projection, the object is placed in the third quadrant and the views are projected onto the planes inside the object.
First angle projection is more intuitive as it mimics the way we naturally view objects, while third angle projection requires mental rotation of the object.
The symbol for first angle projection is a square with a cross inside, while the symbol for third angle projection is a square with a triangle inside.

Popular interview questions of Design Engineer