Answer:
9/40
Step-by-step explanation:
Tan of an angle equals the length of the side opposite the angle divided by the length of the leg adjacent to the angle. Thus, for angle C, AB is opposite it, which is 9, and although both CA and CB are adjacent, adjacent typically refers to the leg, not the hypotenuse, so we want CB, which is 40. Opposite/Adjacent = 9/40
