Start at point x and count down until you are in line with point y. (This will be five units). From the point you just ended at, count across until you get to point y. (This will be 9 units). Five units and nine units are the lengths of your two legs. The Pythagorean theorem is a^2+b^2=c^2. So you then take 5^2+9^2=c^2, or 25+81=c^2, or 106=c^2. Then square root each side, and get 10.2956=c. Therefore the distance between points x and y is 10.2956, or 10.3 if you choose to round.
