Point D is on side BC of triangle ABC with AB=3, AC=6, and angle CAD =angle DAB=60 degrees. What is the length AD?

Question

anonymous · Answer

i dont understand which angle the CAD and DAB indicates. but it wants you to use the 2 sides of abc and the angle to find the 3rd side, because you are gonna need to that 3rd side to complete the triangle with D. then you have enough info on triangle D to calculate the side length AD

mertsj · Answer

Using the law of cosines, side BC = sqrt63.  Then use law of sines to find that angle B =40.9 degrees and since angle BAD = 60, angle BDA = 180-40.9-60=79.1 degrees.
Now use the law of sines again to find that AD = 2