Free maths resources from me, Craig Barton. I am the creator of mrbartonmaths.com & diagnosticquestions.com. I am also the TES Maths Adviser and the host of the Mr Barton Maths Podcast.
A useful and colourful demonstration of Pythagoras theorem in PowerPoint which visually proves that the square of the hypotenuse of a right angled triangle is equal to the squares of the two other sides.
This is great for helping KS3 and KS4 students to understand and memorise the theorem.