I can use similar triangles to explain why the slope “m” is the same between any two distinct points on a non-vertical line in the coordinate plane.
CCSS:
8.EE.6 Use similar triangles to explain why the slope is the same between any two distinct points on a non-vertical line in the coordinate plane; derive the equation for a line through the origin and the equation for a line intercepting the vertical axis at . Define, evaluate, and compare functions.