Answer:
x=8.06
Step-by-step explanation:
Since it's a right triangle, we can use Pythagorean Theorem, which is a^2+b^2=c^2. The hypotenuse, or longest side is always C, so in this case we're going to do C^2-a^2=b^2. 9^2=81, 4^2=16, 81-16=65, square root of 65 is 8.06, so x=8.06
