pdf and cdf for the area of a random triangle in a unit square
https://twitter.com/sfera314/status/1296173013319254016
https://math.stackexchange.com/questions/1236958/the-expected-area-of-a-triangle-formed-by-three-points-randomly-chosen-from-the/1237619#1237619
https://people.kth.se/~johanph/squaref.pdf
xList and yList created using this trick https://www.geogebra.org/m/nrxmfnmf
