We just use the distance formula: For lines, YA and AB, draw a diagram and label all the points!
Thus, we have \(\sqrt{{10^2}-{8^2}}=\sqrt{100-64}=\sqrt{36}=6\) feet.
Similarly, we do it for XA and XB, and since this is \(17\) feet, we get \(\sqrt{17^2-8^2}=\sqrt{289-64}=\sqrt{225}=15\) feet.
Thus, the answer is \(6+15=\boxed{21}\) feet.