Coordinate Geometry
📋 What it is
The coordinate plane locates any point with an (x, y) pair — x across, y up.
🗣️ Coach says
The coordinate plane turns geometry into a map. Every point gets an address: (x, y), where x is how far across and y is how far up. Once shapes have coordinates, you can find distances and midpoints with numbers.
🧠 Memory hook
Plot (x, y): walk ACROSS first (x), then UP (y). "Along the hall, then up the stairs."
😂 Giggle
Why was the parallelogram always getting into trouble?
It never straightened itself out!
😲 Whoa!
Legend says René Descartes invented the coordinate plane while watching a fly on his ceiling — trying to describe its exact position with two numbers.
✅ Quick check: To plot the point (3, 5), which do you move first and how far?
Say your answer out loud first — then reveal.
Move 3 across (x) first, then 5 up (y).
Coordinates are always (x, y): the first number is horizontal, the second vertical.
🧪 Try it! (2 minutes)
Make a grid on paper and play "battleship" — call out (x, y) points to find a hidden dot.