How long before noon does written human history begin?

For which scatterplot is the correlation strongest?

Which equation below is equivalent to sin c=h/a ? a)h= sinc/a b)a=hsinc c)a=sinc/h d)h=asinc

Shown here are the three essential steps in a proof of the pythagorean theorem. comparing the 1st and 3rd steps how are the colored regions related as to the areas? a. yellow+blue=orange b. orange=yellow=green c. yellow+blue=green=orange d. yellow+green=orange+blue