Isosceles Trapezoid Investigation

Interact with the applet below for a few minutes. Then, answer the questions that follow. Be sure to change the locations of the BIG GRAY POINTS each time before re-sliding the slider!
Questions: 1) What new conclusions can you make about an isosceles trapezoid? Describe in detail. 2) Suppose one interior angle of an isosceles trapezoid measures 78 degrees. Determine the measures of its other 3 interior angles. 3) Suppose the length of one diagonal of an isosceles trapezoid measures 16 inches. What would the length of its other diagonal be?