COORDINATE GEOMETRY
by: courtney jones
The coordinate plane or Cartesian plane is a basic concept for coordinate geometry. It describes a two-dimensional plane in terms of two perpendicular axes: x and y. The x-axis indicates the horizontal direction while the y-axis indicates the vertical direction of the plane. In the coordinate plane, points are indicated by their positions along the x and y-axes.
slope = change in y value
change in x value
http://www.onlinemathlearning.com/coordinate-geometry.html
http://www.mathopenref.com/coordintro.html
http://www.cliffsnotes.com/math/geometry/coordinate-geometry/summary-of-coordinate-geometry-formulas
Some coordinate geometry questions may require you to find the midpoint of line segments in the coordinate plane. To find a point that is halfway between two given points, get the average of the x-values and the average of the y-values.
The midpoint between the two points (x1,y1) and (x2,y2) is
For example: The midpoint of the points A(1,4) and B(5,6) is