# Activities

• • • ##### Subject Area

• Math: Algebra I: Quadratic Functions

• ##### Author 9-12

60 Minutes

• ##### Device
• TI-83 Plus Family
• TI-84 Plus
• TI-84 Plus Silver Edition

TI Connect™

• ##### Accessories

TI Connectivity Cable

• ##### Other Materials
This is Activity 5 from the EXPLORATIONS Book: Exploring Mathematics with the CellSheet™ Application

## 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