23. Relationships in Rectangles

Using random integers between 0 and 30, students create lengths and widths of rectangles. In the list facility of the graphing calculator, these lengths and widths can be used to calculate perimeters and areas of the rectangles. Students investigate several relationships using scatter plots—the most exciting is area versus perimeter. Using the ideas of a function forming a boundary on the scatter plot, students discover information about the perimeter and area of a rectangle. This lesson is based on an article “Connecting Data and Geometry” by Tim Erickson found in the November 2001 Mathematics Teacher.

Technology: Graphing calculator.

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