Answer
$5(2+\sqrt 2)h $
Work Step by Step
Using the Pythagorean Theorem for the right triangle, we have:
$2x^{2}=h^{2}$, so $ x=h/\sqrt 2$. The total cost can be written as:
$ C=5\times2x+10\times h=10\times h/\sqrt 2+10\times h=5(2+\sqrt 2)h $