Similarity and congruence

There are 62 NRICH Mathematical resources connected to Similarity and congruence
Pythagoras Proofs
problem

Pythagoras Proofs

Age
11 to 16
Challenge level
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Can you make sense of these three proofs of Pythagoras' Theorem?
Triangle in a Trapezium
problem

Triangle in a Trapezium

Age
11 to 16
Challenge level
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Can you find and prove the relationship between the area of a trapezium and the area of a triangle constructed within it?
The square under the hypotenuse
problem

The square under the hypotenuse

Age
14 to 16
Challenge level
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Can you work out the side length of a square that just touches the hypotenuse of a right angled triangle?
Kite in a Square
problem

Kite in a Square

Age
14 to 18
Challenge level
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Can you make sense of the three methods to work out what fraction of the total area is shaded?
Pinhole Camera
problem

Pinhole Camera

Age
11 to 14
Challenge level
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Make your own pinhole camera for safe observation of the sun, and find out how it works.
Stadium Sightline
problem

Stadium Sightline

Age
14 to 18
Challenge level
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How would you design the tiering of seats in a stadium so that all spectators have a good view?
Fit for photocopying
problem

Fit for photocopying

Age
14 to 16
Challenge level
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Explore the relationships between different paper sizes.
Folding Fractions
problem

Folding Fractions

Age
14 to 16
Challenge level
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What fractions can you divide the diagonal of a square into by simple folding?
Making sixty
problem

Making sixty

Age
14 to 16
Challenge level
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Why does this fold create an angle of sixty degrees?