Chapter 8 of 10All chapters
Chapter 8 of 10
Coordinate geometry
Shape meets algebra.
Points and lines
Placing shapes on axes lets you calculate rather than measure. Distance between two points is Pythagoras; the midpoint is the average of the coordinates.
- A line is y = mx + c, and the slope is rise over run.
- A circle centred on the origin is x squared plus y squared equals r squared.
Why it matters
Every graphic on a screen, every map projection and every CAD model is coordinate geometry underneath.