Math Is Fun Forum

ok so basically i found this thing called 'Archimedes' salinon'
(salinon means salt bowl in Greek btw.)
so this is what salt bowls looked like in BC 200?

The area of the salinon (shaded red) is surprisingly equal to the area of the circle shaded in blue!

Let's say the radius of the two big semicircles is r1, and the radius of the small one is r2. (Let's also define O as the area of the giant semicircle, O1 and O2 as the area of the two big semicircles, and O3 as the area of the smallest one.)
Then, the area of the salinon (S) is:

r1 + r2 is the radius of the blue circle, so the area of the salinon is EQUAL to the area of the circle!

Hey!!!!! :)

I'm XaiDiv, an 8th grader math buff who likes to study and make friends!
I'm from South Korea (yes I'm a bilingual lol) but I'm fluent @ speaking English B)
Feel free to talk to me when you want to make friends :)))))