Proving Triangles Congruent, Part 1
Use the Draw Ray tool to complete the triangle. 
                       - 1st select the ray tool. (find it in the third menu box)
                       - 2nd click the colored point at the vertex E of the new drawing.
                       - 3rd click the lighter colored follow up colinear point to be sure your ray is straight and on the given picture.
                       - 4th click the point at the other vertex D of the new drawing.
                       -  last click the lighter colored follow up colinear point to be sure your ray is straight and on the given picture.
2.  You have created a new triangle in step 1. 
Sketch the new triangle on the grid on your worksheet.