We could find x by finding the leg of the implied triangle.
We could use Pythagorean’s theorem for this
a^2 + b^2 = c^2
Plug in values
(17)^2 + b^2 = (19)^2
289 + b^2 = 361
b = 6 square root 2
We multiply this by two because there are two of these
This makes it 12 square root 2
Subtract this from 31
This will be 31-12 sqrt 2 or 14.029437...