Math and Multimedia Carnival will be hosted here

The Mathematics and Multimedia Carnival is on its 20th edition and will be hosted here.  If you have a blog post about school mathematics, mathematics teaching and learning, multimedia tools, or any related article, you may submit here or email me directly at mathandmultimedia@gmail.com.  The deadline of submissions is on February 18, 2012 and the post date is on February 20.

You may want to visit the following recent math carnivals:

• last month's edition of the Math and Multimedia Carnival
• Math Teachers at Play 46 
• Carnival of Mathematics 85

To those who do not know what a carnival is, I have written a carnival primer in Math and Multimedia. 

Deriving the Equation of the Parabola

Instructions: Move point A to adjust the position of the vertical line and move F along the x-axis as desired. Move C along the line and observe what happens.
This is a Java Applet created using GeoGebra from www.geogebra.org - it looks like you don't have Java installed, please go to www.java.com

Questions
1. What can you say about line a in relation to C and F?
2. Make a conjecture about segments PC and PF.
3.) Suppose P has coordinates (x,y), F has coordinates (2,0), and line d has equation x = 2, write the equation that would describe your conjecture in 2.
4.) Generalize the equation in 3 by changing the coordinates of F to (a,0) and line d has equation x = -d. Find the value of y.

Download GGB file

Tangram Puzzle: Constructing a Square

Move the tangrams to construct a square. Drag the interior to change their position and use the 'blue point' on the vertex to rotate.

This is a Java Applet created using GeoGebra from www.geogebra.org - it looks like you don't have Java installed, please go to www.java.com

Download GGB File

Squaring a Convex Polygon

This applet constructs a triangle with an area equal to the area of any convex polygon ABCDEF. The applet Squaring a Triangle shows how any triangle can be transformed to a square with an equal area. The combination of these two constructions shows how to square any convex polygon.

• Click on point F.
• Drag F to the right as far as it can go.
• Repeat these two steps three times, until the triangle is constructed.

To repeat the construction,  press the "Reset" button or click again on the vertex F of the triangle.

Author: Irina Boyadzhiev   The Ohio State University at Lima
For more details click here.

Download GGB File