Pythagoras Theorem has various ways to prove it. But, one of the interesting process to prove this Theorem is by Fluid.
Water Demonstration of the Theorem:
Consider a model made of plastic or glass so that the squares on the sides and hypotenuse are filled with coloured liquid. The liquid-filled is then allowed to move into the larger square of the hypotenuse and shows that the squares exactly fill the lower square.
This Theorem has many ways to prove it, but the easy and good demonstration of the Theorem is explained in a proper way. Connecting theorems into live demonstration and then explained in a unique way is the best way to connect to the students.