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

Question

Accepted Answer

1st and 3rd angle projection are two different methods used in technical drawing to represent 3D objects on 2D surfaces.

1st angle projection is commonly used in Europe and Asia, where the object is placed in the first quadrant (between the plane of projection and the observer).
3rd angle projection is commonly used in North America, where the object is placed in the third quadrant (behind the plane of projection).
In 1st angle projection, the top view is placed below the front view, while in 3rd angle projection, the top view is placed above the front view.
1st angle projection is more intuitive for visualizing the object in 3D space, while 3rd angle projection is easier for manufacturing and engineering purposes.

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