Problem is in the picture below

Answer:
68.1
Step-by-step explanation:
If those angles are congruent, then all side lengths follow the same ratio.
So the smaller triangle side length of 9 over the small side length of the bigger triangle 21.5, is the ratio for all the sides.
9/21.5 = unknown side / 48
unknown side = 48 * 9/21.5
So to find the length of CD, multiply 48 by our ratio to get ~ 20.1
Add that to our 48 and we get 68.1