Coordinate geometry

Sections

1. 8A Lengths and midpoints of line segments The distance and midpoint formulas, and how to use them to test triangles and quadrilaterals and find circles.
2. 8B Gradients of intervals and lines The gradient formula, parallel and perpendicular gradients, testing for collinear points, and the angle of inclination m = tan θ.
3. 8C Equations of lines Horizontal and vertical lines, gradient–intercept form y = mx + b, and general form ax + by + c = 0, and converting between them.
4. 8D Further equations of lines Point–gradient form, the line through two points, parallel and perpendicular lines through a point, and testing whether three lines are concurrent.
5. 8E Using pronumerals in place of numbers Prove general geometric results with coordinates by placing a figure cleverly and using pronumerals for its vertices.