Pythagoras' theorem

  • Hex
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    Hex

    Age
    11 to 14
    Challenge level
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    Explain how the thirteen pieces making up the regular hexagon shown in the diagram can be re-assembled to form three smaller regular hexagons congruent to each other.
  • Tilted Squares
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    Tilted Squares

    Age
    11 to 14
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    It's easy to work out the areas of most squares that we meet, but what if they were tilted?

  • Garden Shed
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    Garden Shed

    Age
    11 to 14
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    Can you minimise the amount of wood needed to build the roof of my garden shed?

  • Pythagoras Proofs
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    Pythagoras Proofs

    Age
    11 to 16
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    Can you make sense of these three proofs of Pythagoras' Theorem?

  • Where is the dot?
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    Where Is the Dot?

    Age
    14 to 16
    Challenge level
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    A dot starts at the point (1,0) and turns anticlockwise. Can you estimate the height of the dot after it has turned through 45 degrees? Can you calculate its height?

  • Generating Triples
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    Generating Triples

    Age
    14 to 16
    Challenge level
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    Sets of integers like 3, 4, 5 are called Pythagorean Triples, because they could be the lengths of the sides of a right-angled triangle. Can you find any more?

  • Three cubes
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    Three Cubes

    Age
    14 to 16
    Challenge level
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    Can you work out the dimensions of the three cubes?

  • Zig Zag
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    Zig Zag

    Age
    14 to 16
    Challenge level
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    Four identical right angled triangles are drawn on the sides of a square. Two face out, two face in. Why do the four vertices marked with dots lie on one line?
  • Semi-detached
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    Semi-Detached

    Age
    14 to 16
    Challenge level
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    A square of area 40 square cms is inscribed in a semicircle. Find the area of the square that could be inscribed in a circle of the same radius.

  • Inscribed in a Circle
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    Inscribed in a Circle

    Age
    14 to 16
    Challenge level
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    The area of a square inscribed in a circle with a unit radius is 2. What is the area of these other regular polygons inscribed in a circle with a unit radius?