In addition to the plane and the point, the line is a fundamental part of geometry and is one of the most important entities of it; A line is a series of aligned points, that is, they go in the same direction, they also go in succession and are characterized by being continuous and infinite, that is, they have no beginning or end. And when we speak of perpendicular lines, it is an adjective that is used to refer to those lines that are in the same plane, thus forming four right angles; In other words, the parallel lines refer to two secant subtractions that form four congruent angles or when when they intersect they form equal angles of 90º.
So, two lines that meet in the same plane are perpendicular when they form four right angles. On the other hand, in the case of rays, the perpendicularity is shown when the right angles are formed, which usually have the same starting point or origin. And the planes and semi-planes are perpendicular in those cases that form four 90º angles.
The properties of perpendicular lines are: symmetric property, if one line is perpendicular to another, this other one is with the first one; reflective property, this is not fulfilled in perpendicularity, that is, it is not possible for a line to be perpendicular to itself; and the transitive property is not fulfilled either, that is to say that it is not possible that since one line is perpendicular to another, and this other to a third, the first is perpendicular to the third line.
