Stage: 4 Challenge Level: 
Use similar triangles to show the perpendicular form Q meets AB at R where
AR = RB
Then you need to find pairs of congruent triangles
Congruence. Generalising. Right angled triangles. Mathematical reasoning & proof. Manipulating algebraic expressions/formulae. Stage 5 - Reviewed 2012. Dynamical systems. Parallel lines. Inequality/inequalities. Number theory.
Published September 2002.
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