The lines that form the letter T are perpendicular.
From the Latin perpendiculāris , perpendicular is a term used in geometry to name the plane or line that, with another plane or line, creates an angle of ninety degrees . It is important to note that there are various forms of perpendicularity relationships.
Two lines that lie in the same plane are perpendicular when they form four right angles. In the case of ray rays , perpendicularity appears when right angles are developed, usually with the same point of origin. The planes and semiplanes, finally, are perpendicular in cases where four dihedral angles of ninety degrees are formed.
It is possible that a relationship of perpendicularity may even develop between the elements mentioned above (straight, semi-straight, plane, semi-plane), although considered 2 by 2.
Perpendicular vs. parallel
It is important to emphasize that when talking about perpendiculars we find another term that is related to them and that are sometimes confused. We are referring to those known as parallels.
In this case, we have to make it clear that parallel lines can be defined as those that never intersect, that are equidistant and that no matter how much they are extended, they never meet at a point.
However, opposite to those are the perpendicular lines which, as we have previously analyzed in depth, are the ones that are characterized because they are the ones that intersect with others forming what is a right angle. Therefore, we can establish that the difference between parallel and perpendicular lines is 90º.
In order to better understand this clear differentiation, there is nothing better than using two examples. Thus, the lines that make up a sign on the ground of a zebra crossing or those that delimit the width and length of a roadway are parallel straight lines. For their part, perpendicular are the lines that give shape to the mathematical sign of addition: +.
It is possible to draw perpendicular lines with the help of a square.
Properties of perpendicularity
Among the properties of perpendicularity, there are uniqueness (through a point belonging to a line, in a certain plane, only one perpendicular line passes) and symmetry (when one figure is perpendicular to another, this one will also be perpendicular to the first ). In the case where two lines intersect and create congruent adjacent angles, they are perpendicular, as are planes that create perpendicular adjacent dihedral angles.
Another property of perpendicularity states that the sides of an angle and its opposite rays determine two perpendicular lines. In the same way, those sides that are part of a dihedral angle and their opposite half-planes also generate two perpendicular planes.
Other uses of the term perpendicular
It should be noted that the vertical line that arises from the intersection of the maximum flotation with the edge of the stem of a boat is known as the bow perpendicular .
Finally we have to highlight the existence of a book that takes the concept we are addressing as an integral part of its title. This is the work "The Perpendicular History", written by Carlos Fonseca Terán, in which a review of what the Sandinista revolution is while showing what the current reality of Nicaragua is.