If ac = 3, bc = 5, and ab = 7, find ad:
2 5/8
4 1/5
4 3/8
11 2/3

1.    

Step-by-step explanation:

We can see that CD is angle bisector, So we will use angle bisector theorem which states that the angle bisector of an angle of a triangle divides the opposite side in two segments that are proportional to the other two sides of the triangle.

We can set up an equation as:  

Upon substituting our given values we will get,

Cross multiplying our equation we will get,

Therefore, the length of AD is units and 1st option is the correct choice.