Trapezoid Midsegment Action!

Interact with the applet below for a few minutes. Then, answer the questions that follow. 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 helps justify this?) 2. The thickest segment with three tick marks is called a midsegment of a trapezoid. Define the term "midsegment of a trapezoid" without looking up its definition on another site. 3. What two facts/properties about the midsegment 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 midsegment be? 5. Suppose a trapezoid has a midsegment 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 a length of 0. Then re-slide the slider. What other theorem(s) previously learned does this applet now show? BONUS: 7. Use coordinate geometry to prove each of the 2 facts that you listed in your response to question (3) above. Here's a setup to help get you started (see below):