Cosine is

which applies to a right triangle. I hope that helps you.
Answer:
The answer is 8.
Step-by-step explanation:
The scale factor between the figures is 2/3, this means that the ratio of the smaller figure to the larger figure is 2/3:
.
So when a side of the the larger figure is 12 then:

Therefore
.
Thus the length of the corresponding smaller side is 8.
Thank you for posting your question here at brainly. The answer to the above question is the first one in the choices which is 15. Below is the solution:
<span>
3x + 10 = 55
Subtract 10 from each side...
3x = 45
Divide by 3...
x = 15</span>
what that person said.........;
Well, after doing all that math, here is what I came up with, I hope this helps! :) -1600x^2+28265x-21830