Angle Bisector Theorem (Part 1)

The applet below contains an angle and a point D that always remains EQUIDISTANT from the SIDES of this angle. Complete the direction in the applet below (first) and then proceed to the questions below the applet.
Questions: 1) What does the locus (set of points) of all the green traces of point D seem to form? How would you describe this set of points in detail? (Recall a previous vocabulary term). 2) Click the checkbox in applet above to either confirm your answer to question (1) or help you better answer question (1). 3) Use what you've observed to complete the following statement: "If a point is equidistant from the sides of an angle, then that point.....