Parallel projection in which the projection direction is perpendicular to the projection target (or

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

**Orthogonal projection on a line in a plane**

Transformation in a plane determined by two perpendicular lines*d*(line on which the figures are projected) and*d*_{1}which determines the projection direction that applies all points P on 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.

- Orthogonal 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).In a Cartesian plane, the coordinates of the points of the plane are obtained by orthogonal projection from the point on each of the axes. **Orthogonal projection on one plane in space**

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

- Orthogonal projections on a plane preserve the order of the points and the parallelism of the figures.
- Orthogonal projections are used to represent an object in three-dimensional space on three planes that are perpendicular to one another, called
*top view*,*side view*, and*front view*.