how to derive pi

how to derive pi with high school / college level trig. Pythagoras proof and pi are two very common, basic, fundamental laws that we learn even at an early age. Yet I couldn't find any info online about how to derive them and I wasn't taught them in school. So after I figured out how to derive them, I posted them online for others to enjoy and, dare I say, appreciate their beauty.

I think up math problems for fun just as a way of doodling. I'm putting these math doodles online because I hadn't came across them in any of my math classes and hadn't found similar videos about them online. enjoy.

derive