shows how to find the volume of cylindrical and rectangular granaries as well as how to find the area of a circle.
https://owlcation.com/stem/What-is-Trigonometry
ref - https://www.reddit.com/r/todayilearned/comments/dec3gy/til_the_rhind_mathematical_papyrus_written_1000/
origin - https://www.pipiscrew.com/?p=15427 rhind-mathematical-papyrus-written-1000-years-before-pythagoras