AutoCad :: How To Use Constrain To Bisect Angle In Geometry

In triangle ABC, AD is drawn as angle bisector and BE is drawn perpendicular to AD. I want to draw these two lines and triangle ABC by means of constrains, so that when I move point A (make it bigger or smaller), I can get those two lines move automatically. What kind of constrains should I use? For triangle itself, I use "coincident" constrain. I think this part is correct. Whenever I move a vertex after selecting a line and using red grips, it responds and triangle reshapes. Do we have angle bisector constrain? I draw angle dimension line for two equal angle and tried to impose equal constrain for these two angle but couldn't succeed.