Here is a 28 page lesson on teaching the Pythagorean Theorem. Students are led through some vocabulary and taught the formula. They then learn how to use the formula to find the hypotenuse when two legs are given and they learn how to find a leg when one leg is given and the hypotenuse is given. There are plenty of practice pages and each page contains a pull tab that reveals the answer. Sometimes the answer comes from a perfect square and sometimes they have to use the "approximately to" symbol.