Stage: 4 Challenge Level: 
If you are having trouble making sense of any of the proofs, click on the pictures to see a hint for each one:
Similar triangles. Stage 5 - Reviewed 2012. Number theory. Pythagoras' theorem. Mathematical reasoning & proof. Generalising. Dynamical systems. Inequality/inequalities. Creating expressions/formulae. Manipulating algebraic expressions/formulae.
Published September 2009.
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