- Coordinate GeometryThe number planeDistance between two pointsMidpoint and Endpoint Coordinates Action!Slope: Intuitive IntroductionGradient (or slope) of a linePerpendicular Lines Investigation (VB)Blueprint Equation of a Line (I)Writing the Equation of a Line (I-VA)Equations of vertical and horizontal linesPerpendicular Bisector DefinitionPBT (Part 2) - Quick