Engineering Graphics

Projections of Planes

Plane surface (plane/lamina/plate)

A plane is a surface having length and breadth formed by joining three non collinear points. Planes are surrounded by straight/curved lines and may be either regular or an irregular. In regular planes all the sides are equal whereas in irregular planes they are not equal.

Positioning of a Plane surface

Following are the positions in which the plane surface can be positioned with reference to the three planes

·         Parallel to one of the principal planes and perpendicular to the other two.

·         Perpendicular to one of the principal planes and inclined to the other two.

·         Inclined to all the three principal planes.

Projections of a Plane surface

When any plane surface is held parallel to the one reference plane then it is perpendicular to the other two panes. The projection of the plane on the plane to which it is perpendicular will be a line called as line view. The projection of plane on to the plane to which the given plane is paralle will give the true shape of the plane as all the edges will be parallel to the reference plane on which the plane is projected. When the plane is inclined to any reference plane its corresponding projection will give apparent shape of the plane

   A few examples of projections of plane surfaces are illustrated below:

A) Plane surface parallel to one plane and perpendicular to the other two 

B)Plane parallel to HP and perpendicular to both VP and PP 

C) Plane parallel to PP and perpendicular to both HP and VP 

D) Plane surface perpendicular  to one plane and inclined to the other two

For further reading the students must refer the following link

http://nptel.ac.in/courses/112103019/24

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