Stage: 4 Challenge Level: 
The red triangle is an enlargement of the original by a scale
factor of a. The lengths of its sides are marked on.
Can you mark on the lengths of the blue triangle? What can you say about the resulting triangle when the two are joined together?
Can you mark on the lengths of the blue triangle? What can you say about the resulting triangle when the two are joined together?
Similarity. Mathematical reasoning & proof. Pythagoras' theorem. Scale factors. Interactivities. Number theory. Enlargements. Right angled triangles. Inequality/inequalities. Manipulating algebraic expressions/formulae.
Published December 2001,January 2002.
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