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  • Early Years Foundation Stage

Angles in Three Squares

Age 14 to 16
Challenge Level Yellow starYellow starYellow star
  • Problem
  • Getting Started
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The picture below shows three squares.
Surprisingly, $c = a + b$.
Can you prove it?

 

Once you've had a chance to think about how to prove it, click to reveal the diagram below.
Can you use the diagram to help you construct a proof?
 

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The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.

NRICH is part of the family of activities in the Millennium Mathematics Project.

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