Pythagorean Theorem: Using Similar Triangles
This note (surely not new) is what I believe is the essence of the
original proof (300 BCE) using similar triangles -- except it has
been shortened and illuminated by pruning some ingredients.
Pythagorean Theorem Using Similar Triangles (pdf)
It may be useful to compare this with other recent presentations.
They involve more computation -- and led me to write this for my class.