Geo-Calc is Macintosh shareware for calculating the area, perimeter, sides, angles, and other measures of two- and three-dimensional shapes such as ellipses, rectangles, triangles, trapeziums, parallelograms, polygons, prisms, cylinders, cones, pyramids, and spheres.

If entered values do not describe a valid geometrical figure, Geo-Calc highlights the specific problem and suggests solutions. Also available in German and Norwegian.

Areas of the site includes:

• Introduction movie
• Installation
• How to use Geo-Calc
• Download
• Registration
• Languages
• System Requirements
• Version History

Current interactives include:

• Qualitative Grapher
• Piecewise Linear Grapher
• Linear Transformer
• Function Analyzer
• Quadratic Transformer
• System Solver
• Plop It!
• Proportioner

The Concord Consortium freely offers these interactives online, as well as a link to download them all for offline use.

http://www.84silver.com/

Texas Instruments has three different contests:

GraphiTI Design Contest
Create your own GraphiTI design and you could win a $1,000 shopping spree and a TI-Navigator classroom learning system and 30 TI-84 Plus Silver Edition Graphing Calculators for your school.

Deadline: September 29, 2006 at 11:59 p.m. ET

View the Contest Rules:

http://www.84silver.com/contest_rules.php

View the 2005 Winners:

http://www.84silver.com/2005_winners.php

 

Texas Instruments $8,400+ Achieve More Scholarship

Students, parents, and educators can nominate a scholarship winner.

Deadline: December 20, 2006

View the Contest Rules:

http://www.84silver.com/win_scholarship_rules.php

 

Tell Us About Your Teacher Essay Contest

In 300 words or less, tell how your teacher has helped you understand mathematics by using Texas Instruments technology in the classroom. The teacher you're nominating must approve your essay in order for it to be officially entered to win.

Deadline: September 29, 2006

View the Contest Rules:

http://www.84silver.com/win_essay_rules.php