Answer: 37.0
Explanation:
Using Pythagorean theorem we can solve for the missing side of the triangle.

Square 24.6 and 16.2

Then subtract 262.44 to the other side to isolate b.

Now square root both sides to solve for b.
b = 18.592
Then multiply b by 2 to find x.

x = 37.025
When rounded it is 37.0.