1. Plotting Points
Ask: How do you plot a point?
In the Cartesian Coordinate System, you plot an x-coordinate, then a y-coordinate. Points are written as ordered pairs (x, y).
But there are other coordinate systems:
In the Polar Coordinate System, you plot an angle and a radius. Points are written as (r, theta).
In Polar Coordinates, r is a directed distance. theta is the angle from the positive x-axis and measured in a counter-clockwise direction.
2. Examples of plotting points in the Polar Coordinate System:
Give some names for points B and D.
For each point, give 4 different names in the form: (+, +), (+, -), (-, +), and (-, -).
3. Play Tic-Tac-Toe or "Connect Four" with Polar Coordinates.
Split the class into two teams.
The object of the game is to get four in a row -- along a radius, along a circle, or "diagonally."
Take turns having students give coordinates.
Here is the Game Board:
