[b]Drag the vertices of the triangle. Notice the changes in the angle measures.[/b][br]1) Are there any restrictions on the angle measures?[br]2) What do you notice about the [i]sum [/i]of the angle measures?[br][b]Click the box that says "Show Parallel Line." Again drag the vertices of the triangle and notice the changes in the angle measures.[/b][br]3) What do you notice about the measures of the orange angles? How could you prove that this is always true?[br]4) What do you notice about the measures of the green angles? How could you prove that this is always true?[br]5) What is the relationship between the three angles that share a vertex at B?