Answer:
4/5
Step-by-step explanation:
In a right triangle such as this one
cos (angle) = adjacent leg / hypotenuse
cos(k) = KL / 15
You will need to find the leg length KL using Pythagorean Theorem
15^2 = 9^2 + (KL)^2 KL = 12
then cos k = 12/15 = 4/5
