First Angle and Third angle projection

A projection is defined as an image or a drawing of an object made on a plane.

In technical drawing and computer graphics, a multi view orthographic projection is an illustration technique in which up to six pictures of an object are produced, with each projection plane parallel to one of the coordinate axes of the object.

An Orthographic projection is a parallel projection in which the projectors are parallel to each other and perpendicular to the plane of projection.


Two main types of Orthographic projection are Multi-view projection and Axonometric projection. Multi-view projection is divided in four types:-

1) First Angle Projection
2) Second Angle Projection
3) Third Angle Projection
4) Fourth Angle Projection

In the current session writing is focused on First Angle Projection and Third Angle Projection.

In first-angle projection, the object is conceptually located in quadrant I, i.e. it floats above the Horizontal Plane(H.P) and before the Vertical Plane(V.P).The observer who is theoretically at infinite distance, looks at the object from the front. The rays of sight are parallel to each other and perpendicular to the V.P. The view obtained on the V.P is similar to the front surface of the object and is known as front view. It may be noted that front view shows only the length and height of the object. It does not inticate the width.