Define: horizontal and vertical

The horizon is the "apparent junction of earth and sky."

The following is a number line written horizontally.

   <--+---+---+---+---+---+---+---+---+---+---+-->
         -5  -4  -3  -2  -1   0  +1  +2  +3  +4  +5

The vertical is "perpendicular to the plane of the horizon or to a primary axis." [Perpendicular is "being at right angles to a given line or plane."]

The following is a number line written vertically.

      ^
      |
   +5 +
      |
   +4 +
      |
   +3 +
      |
   +2 +
      |
   +1 +
      |
    0 +
      |
   -1 +
      |
   -2 +
      |
   -3 +
      |
   -4 +
      |
   -5 +
      |
      v
Right Angle

Perpendicular lines intersect and their point of intersection is called the origin. Perpendicular lines form four right angles at the origin. A right angle measures ninety degrees (90°).

With respect the Cartesian coordinate system, the horizonal line is the x-axis and the vertical line is the y-axis.

           | <-- vertical-axis (y-axis)
           |
           |
           |
   --------o-------- <-- horizonal-axis (x-axis)
           |\
           | \
           |  o is the origin
           |   

Note: The Cartesian coordinate system was developed by French mathematician and philosopher Rene Descartes in approximately 1637.

RoadHacker:: Horizon/Vertical Slideshow [opens new window]


Creator: Gerald Thurman [gthurman@gmail.com]
Created: 09 February 2005
Last Modified: Saturday, 05-Jan-2013 11:18:13 MST

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This work is licensed under a Creative Commons Attribution 3.0 United States License.