Geometric transformation in geometric space characterized by a projection direction and a target figure.

The target figure can be a line, a plane, a sphere, etc.

**parallel projection on a line in a plane**

Transformation in a plane determined by two intersecting lines*d*(line on which the figures are projected) and*d*_{1}(which determines the projection direction) that apply all points P of the plane on a point P‘ so that P‘ is the point of intersection of*d*with the parallel to*d*_{1}that passes through P.

- Parallel projections on a line in a plane preserve the order of the points on the segments. If
*p*is a parallel projection of the plane on a line*d*according to a direction*d*, then no matter what the points A and B of the plane are so that the line AB intersects with_{1}*d*,if A<B, then_{1}*p*(A) <*p*(B). **Parallel projection on a plane in space**

Transformation in space determined by a plane*p*(plane on which the figures are projected) and*d*(line that determines the projection direction) that applies all points P of the plane on a point P‘ so that P‘ is the point if intersection of*p*with the parallel to*d*that passes through P.