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Tuesday, December 16, 2008
Archimedes' Book of Lemmas, Proposition #7
Problem 646: Square, inscribed and circumscribed circles Exercise your brain. Archimedes wrote the "Book of Lemmas" more than 2200 years ago. Solve the proposition #7 (high school level) and lift up your geometry skills.
Let Circle Ci's radius be r, then Circle Cc's radius is (sqrt2)r. Area Circle Cc=pi*2r^2, Area Circle Ci=pi*r^2, therefore Area Circle Cc=2 Area Circle Ci.
if one side of the square is S1 then two half circles = S2 because if you put them together it looks like it. Also, the radius of S2 is like half of one side of a square
Let Circle Ci's radius be r, then Circle Cc's radius is (sqrt2)r.
ReplyDeleteArea Circle Cc=pi*2r^2, Area Circle Ci=pi*r^2, therefore Area Circle Cc=2 Area Circle Ci.
if one side of the square is S1 then two half circles = S2 because if you put them together it looks like it. Also, the radius of S2 is like half of one side of a square
ReplyDeletehttps://photos.app.goo.gl/kZvQdn19FH2wX9pc8
ReplyDeleteLet radius of S1 be r, radius of S2=r*sqrt2
ReplyDeleteArea of S1=pi*r^2
Area of S2=pi*(r*sqrt2)^2=2pi*r^2=2S1