# Trapezoid Median (Midsegment) Action!

**Be sure to change the locations of the white points each time before re-sliding the slider!**

## 1.

How do you know the **quadrilateral **initially constructed is a **trapezoid**?
(What postulate or theorem helps justify this?)

## 2.

The **thick black segment (with three tick marks)** is called a **median (or midsegment) of a trapezoid**. Define the term **median of a trapezoid **without looking up its definition on another site.

## 3.

What two facts/properties about the **median of a trapezoid** does this applet illustrate?

## 4.

Suppose the bases of the trapezoid above measured 14 inches and 26 inches. What would the length of its median be?

## 5.

Suppose a trapezoid has a median with length 35 inches and one base measuring 23 inches. What would the length of its other base be?

## 6.

Now move any point so that one of the trapezoid's bases has length = 0. Then re-slide the slider. What other theorem(s) previously learned does this applet now show?

## 7.

Prove each of these 2 facts (you listed in your response to question (3) above) true using the format of a 2-column, paragraph, or coordinate geometry proof.