Use the sliders to change the slopes of the two linear functions so that the shape in middle of the red outside square is also a square. Moving Point G increases or decreases the size of the external square. Screencast tutorial for using the applet.

Find two combinations of slopes that form an inscribed square within the bigger square. Record the slopes for the original and perpendicular function.

What do you notice about the slopes of functions when the inscribed square is formed?

Explain why the lines are perpendicular when the square is inscribed in the bigger square.

Create a graph of your own with 2 perpendicular functions and show they are perpendicular by creating a square and inscribed square.

Blair Miller, Created with Geogebra

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