Common Core State Standard: 8.EE.B.6

Domain: Expressions & Equations

Theme: Understand the connections between proportional relationships, lines, and linear equations

Standard Description: 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; derive the equation y =mx for a line through the origin and the equation y = mx + b for a line intercepting the vertical axis at b.