Answer:
Correct answer is 8.9
Step-by-step explanation:
When you use the Pythagorean theorem formula a^2 + b^2 = c^2, we can easily calculate the missing side by plugging in the given numbers. So when you do the math, 2.8^2 + 8.5^2 it will give you 80.09, then when you square root it, it will be 8.9. And that is your answer
