Section 3.8 – Analyzing Polygons Using Coordinates

Slope =

m = , where ( and are points on a coordinate plane

slope-intercept form: y = mx + b (where m = slope and b = y-intercept)

In a coordinate plane, two non-vertical lines are parallel if and only if they have the same slope. Any two vertical lines are parallel.

In a coordinate plane, two non-vertical lines are perpendicular if and only if the product of their slopes is -1 (the slopes are negative reciprocals). Any vertical line is perpendicular to any horizontal line.

Midpoint Formula: