Answer:
C. c^2=a^2+b^2-2abcos(90°)
Step-by-step explanation:
This is the law of cosine.
Answer number 3
Step-by-step explanation:
Use the Pythagorean theorem

to find the missing side length of a right triangle
In this case, after you plug in the given numbers your equation is

Then, Just solve that equation for y.



y = 16
So the answer is B, 16 cm.
I hope this helps, please feel free to ask questions if you're still confused :)