Reflection in a Square

Point E is reflected in the sides of the square. Drag E to see the change in the images.[br]What properties do you notice in the quadrilateral formed by the red points?[br]By dragging E to different positions, what kind of quadrilaterals can be made.
If we start with other shapes (instead of a square) for generating the mirror images, what different results will we have?[br]In what other ways would you extend this problem?

circles

a single construction that may generate different geometry textbook problems
circles

questions about a cube

What different triangles can be formed?[br]What different polyhedrons can be formed?
questions about a cube

graphing an antiderivative function

graphing an antiderivative function[br]see the construction at http://youtu.be/LospYWEhnDg
graphing antiderivative function

Quadratic and Linear Graphs

compare quadratic and linear graphs
Quadratic and Linear Graphs

Rectangle and a Square

Drag the green dot to vary the rectangle. [br]Drag the red dot to find out which is bigger.
Which is bigger, the rectangle or the square?
Introduce the identity, difference of two squares, through a problem about comparing areas. See the making of this file in YouTube -> [url=http://youtu.be/v809gcQTfD4 ]http://youtu.be/v809gcQTfD4 [/url]

combining spirals

combining spirals from dilation and rotation of triangles
combining spirals

making strange shapes from a circle and quadrilateral

Have some fun with the section formula (point of division). Use the slider to switch between a square and circle.
Click 'control' to display the original shapes. Drag the vertices to experiment with different starting quadrilateral.
[b]'[color=#ff0000]Pixar in a Box[/color]'[/b] has similar materials about modelling and 'weighted averages' -> [url=https://www.khanacademy.org/partner-content/pixar/environment-modeling-2]see the page on Environment Modeling[/url][br]https://www.khanacademy.org/partner-content/pixar/environment-modeling-2
These slides show more examples based on this applet.
How to make this file:

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