There’s some resources below, but first… a nice desmos activity to help introduce the concept with a fun task first before introducing Pythagoras to students.
See this link to using an origami activity to teach Pythagoras! (scroll to bottom of article)
Nice visual water demonstration seeing how pythagoras works: http://blogs.rosebank.nsw.edu.au/slotter/2014/04/16/pythagoras-theorem-water-demo/
Desmos titles this one “Pythagorean Theorem Proofs without words!”
ONE OF DAN MEYER’S QUESTION SCENARIOS:
Need to use Pythagoras and some thinking to work it out!
Used for year 8, for students to practice being able to find both hypotenuse and short sides – to solve a riddle!
Another golf desmos activity – once they have the hang of Pythagoras or to check understanding maybe?
Can use the Taco Cart activity on Desmos as well for an application once they understand it.
NB: Robert K has this scarecrow activity as an intro… but not sure the context will capture interest?
How about this video – from about the mid-point – to inspire/challenge some thinking!! Talking about the pursuit of the perfect cuboid. An interesting video anyway discussing what mathematicians generally do (problem solving!)
And for an extension – check out the Q in the image below: