Education Technology

# Ratio of Areas

9-12
60 Minutes
TI Connect™
TI-83 Plus Family
TI-84 Plus
TI-84 Plus Silver Edition
This is Activity 5 from the EXPLORATIONS Book: Exploring Mathematics with the CellSheet™ Application
Lessons

# Ratio of Areas

Activity Overview

In this activity, students use the CellSheet™ Application to determine geometric ratios of areas. Students determine the position of the vertices of a square that has all four vertices on the sides of a larger square and has a specified area. They also learn how quadratic functions can model geometric ratios.

Before the Activity

• Install the CellSheet on the calculator using the TI Connect™, TI-Connectivity cable, and Unit to Unit cables
• See the attached PDF file for detailed instructions for this activity
• Print pages 51 - 52 from the attached PDF file for your class
• During the Activity

Distribute the pages to your class.

• Use the quadratic equation and for different x-values find the corresponding y- values
• Determine the slope of the secant line that passes through 2 points
• Determine the Δx - slope relationship
• For values of x, use the cubic equation to find the corresponding y-values
• Determine the slope of the secant line and Δx - slope relationship
• Compare the Δx - slope pattern for the cubic quadratic function curves
• After the Activity

Students will complete the worksheet and answer questions.

Review student results:

• As a class, discuss questions that appeared to be more challenging
• Re-teach concepts as necessary