Answer:
5
Step-by-step explanation:
We need to use Pythagoras' theorem.
For this we can use the pythagoras formula a^2+b^2=c^2 and rearrange this
We then will have 8^2+b^2=89
(because 89(sqrt) squared is 89)
We can then solve for what x is.
We take away 64 from 89 which is 25
the square root of 25 is 5
Therefore x=5