Question 144274
You can use Pythagorean theorem, Or you can take a quick look and see the trianlge is in the ratio 3:4:5. In this case, 9:12:15

Using the Pythagorean theorem. Find the diagonal as
{{{c^2 = a^2 + b^2 }}}
{{{c^2 = 9^2 + 12^2 }}}
{{{c^2 = 225}}}
{{{c = 15}}}

So the cost is 15*10 = 150