Simply substitute 14 in place of S in the equation: âš(14 to the 2nd power + 14 to the 2nd power) or âš(14^2 + 14^2) Next, multiply 14 by itself to get 196, and replace both of the 14 to the 2nd powers: âš(196 + 196) Now add to get 392: âš(392) Finally, take the root and round: 20 inches