Answer:
x ≈ 15.59
Step-by-step explanation:
We need to use the Pythagorean Theorem to solve for x. The equation for that is a^2 + b^2 = c^2. Side a is 9. Side b is x. Side c is 18 and 18 is also the hypotenuse. Let's solve for x(side b):
a^2 + b^2 = c^2
9^2 + x^2 = 18^2
81 + x^2 = 324
Subtract 81 from both sides to get x^2 alone on one side.
x^2 = 243
Square root both sides to isolate x.
x = 9sqrt3)
x ≈ 15.59