Creation of this applet was inspired by a tweet from Matthew Scroggs that was retweeted by Martin Gardner tweet.
Interact with the applet for a few minutes.
As you do, feel free to adjust the

**blue slider**and the locations of the**white points**. Answer the questions that follow.## 1.

How do the dynamics illustrated above (* informally) imply *that the areas of the two smaller right triangles add to the area of the largest right triangle?

## 2.

How can you formally prove what this applet informally illustrates?