Question 186611
A right triangle with 45 degrees will be an isosceles right triangle  whose sides will be in the ratio 1: &#8730;2 : 1, where &#8730;2 is the hypotenuse.
Since the Hypotenuse is &#8730;2, the other two sides are 20/&#8730;2 = 10 &#8730;2  inches each.

If you want their lengths in decimals they will be 14.142 inches each