Explanation:
When a line is parallel to one plane and inclined to the other, the projection of the line on the plane to which it is parallel will show its true length. The projected length on the plane to which it is inclined will always be shorter than the true length.
S. No. |
Orientation/Position of line |
Front view or elevation |
Top view or plan |
1. |
Line parallel to both H.P. and V.P. |
True length, parallel to xy |
True length, parallel to xy |
2. |
Line perpendicular to H.P. |
True length, perpendicular to xy |
Point |
3. |
Line perpendicular to V.P. |
Point |
True length, perpendicular to xy |
4. |
Line inclined at θ to H.P. and parallel to V.P. |
True length, inclined at θ to xy |
Shorter than the true length, parallel to xy |
5. |
Line inclined at ϕ to V.P. and parallel to H.P. |
Shorter than the true length, parallel to xy |
True length, inclined at ϕ to xy |
6. |
Line situated in H.P. and inclined at ϕ to V.P. |
Shorter than the true length, lying on xy |
True length, inclined at ϕ to xy |
7. |
Line situated in V.P. and inclined at θ to V.P. |
True length, inclined at θ to xy |
Shorter than the true length, lying on xy |
8. |
Line situated both in H.P. and V.P. |
Both front and top views are the true length and coincide on xy |