# Special Quadrilateral: Theorem 2

- Author:
- Tim Brzezinski

- Topic:
- Angles, Parallelogram, Quadrilaterals

Interact with the applet below for a few minutes.
Then, answer the questions that follow.
Feel free to move the BIG WHITE POINTS anywhere you'd like!
You can also adjust the size of the pink angle by using the slider.

## 1.

What conditional (if-then) statement can you write based upon the logical order of dynamic phenomena (i.e. actions) you observed in this applet?

## 2.

How does this conditional (if-then) statement compare with the conditional statement you previously wrote for **this applet**?

## 3.

Write a 2-column, paragraph, or coordinate-geometry proof of the conditional statement you wrote for (1) above.

## 4.

What other previously learned theorem was evidenced in the dynamics you observed above?