This is the first step in creating Euclid's proof of Pythagoras' Theorem.
Require students to demonstrate the triangles' congruence using SAS.
Prompt questions:
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[*]Which side of the pink triangle is equal to side AB in the yellow triangle?
How can you be [i]sure[/i] it's always the same?
Which side of the pink triangle is equal to side AG in the yellow triangle?
How can you be [i]sure[/i] it's always the same?
Look at angle BAG in the yellow triangle. Which angle does it correspond to in the pink triangle?
How could we be certain these are the same?
Notice BAG is the sum of GAD + 90. How does that help?
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