Activities

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- Teacher Files
- Teacher Notes DOC
- Teacher Notes PDF
- Student Files
- Student Activity DOC
- Student Activity PDF
- Activity Program 1 (EDGE1)
- Activity Program 2 (EDGE2)
Alignment
- Standards Alignment
- Textbook Alignment
Subject Area
- Math: Algebra II: Equations
- Math: Algebra II: Radical Functions
- Math: Algebra II: Rational Expressions
Author

Texas Instruments
Level

9-12
Activity Time

45 Minutes
Device
- TI-83 Plus Family
- TI-84 Plus
- TI-84 Plus Silver Edition
Software

TI Connect™
Applications
- Cabri™ Jr. for TI-83 Plus and TI-84 Plus
Accessories

TI Connectivity Cable
Unit-to-Unit link cables
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Living on the Edge

Published on 04/24/2011

Students find the edge length of an octahedron when given its volume.

Students build a solution to a rather complex problem—finding the edge length of an octahedron given its volume—by solving two simpler problems.

First, students find a formula for the edge length of a square given its area.
After testing this formula by comparing points on its graph with the measurements of a model square, they write an equivalent formula with fractional exponents and substitute values to find the edge length of a particular square. Students will repeat this process for the formula for the edge length of a cube given its volume.
Finally, students solve an equation involving several different radical expressions to find a formula for the edge length of an octahedron given its volume, and use it to solve the original problem.