Definition of the intersection of two lines
Math Open Reference

Animation showing that in any triangle, the centroid, circumcenter and orthocenter are always collinear  they always lie on a straight line, called the Euler line.
Math Open Reference

CPCTC  a way to remember 'Corresponding Parts of Congruent Triangles are Congruent'
Math Open Reference

Definition of a ray when the defining points are on the coordinate plane
Math Open Reference

A method for finding the distance from a point to a vertical or horizontal line in coordinate geometry
Math Open Reference

A method for finding the distance from a point to a line in coordinate geometry using trigonometry
Math Open Reference

A method for finding the distance from a point to a line in coordinate geometry using a formula
Math Open Reference

A method for finding the distance from a point to a line in coordinate geometry using two line equations
Math Open Reference

Three methods are discussed for finding the distance from a point to a line in coordinate geometry
Math Open Reference

The coordinate plane defined with description of x,y axis, quadrants, origin.
Math Open Reference
