These Four websites will l help you learn about Pythagorean Theorem.
The two websites down below us really helps you do the Pythagorean Theorem by.
http://www.mathsisfun.com/pythagoras.html
The website from math is fun will help you more to do the Pythagorean.
http://www.ixl.com/math/grade-8/pythagorem-theorem-find-the-perimeter
http://www.ixl.com/math/grade-8/pythagorem-theorem-find-the-perimeter