Found it, http://www.cut-the-knot.org/proofs/IntersectingChordsTheorem.shtml . The proof is via construction of similar triangles so it looks like the only thing circular about this proof is the drawing. Nice.

I agree with the poster who said that this is a very nice proof. I recommend Eli Maor's book, The Pythagorean Theorem: A 4,000-Year History, for more proofs and wonderful commentary.

Is there a proof of this circle theorem that is independent of Pythagoras' theorem?

ReplyDeleteFound it, http://www.cut-the-knot.org/proofs/IntersectingChordsTheorem.shtml . The proof is via construction of similar triangles so it looks like the only thing circular about this proof is the drawing. Nice.

ReplyDeleteI agree with the poster who said that this is a very nice proof. I recommend Eli Maor's book, The Pythagorean Theorem: A 4,000-Year History, for more proofs and wonderful commentary.

ReplyDeletePlease help me to find Pythagorean Theorem Practice paper .I am searching these and want to strong my comcepts .

ReplyDelete