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Age 14 to 16
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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? 
Which sides match together to make a larger triangle?
What can you say about the angles of the resulting triangle when the red and blue triangle are put together?
What is the scale factor of enlargement from the original triangle to the last triangle?
 

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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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