There is a visual proof of Pythagoras theorem. I’ve made an interactive version. Recall the famous theorem about the sides of a right angle triangle:\( c^2 = a^2 + b^2 \)
where c is the side of the hypotenuse, a and b are the other two sides.
The two squares at the bottom have the same area because they both have sides a+b.
The one on the left is the c square plus four triangles.
The one on the right is the a square plus the b square plus four triangles.
Both squares have four equal triangles and the same area, so whats left over must also be equal.
Drag the anchor point (the little circle) to change the triangle.
Years ago I made a painting with this proof: