Pythagoras' theorem

  • Out of the Window
    problem

    Out of the window

    Age
    14 to 16
    Challenge level
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    Find out how many pieces of hardboard of differing sizes can fit through a rectangular window.
  • Classic cube
    problem

    Classic cube

    Age
    16 to 18
    Challenge level
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    The net of a cube is to be cut from a sheet of card 100 cm square. What is the maximum volume cube that can be made from a single piece of card?
  • Golden Construction
    problem

    Golden construction

    Age
    16 to 18
    Challenge level
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    Draw a square and an arc of a circle and construct the Golden rectangle. Find the value of the Golden Ratio.
  • Right Angled Possibilities
    problem

    Right angled possibilities

    Age
    14 to 16
    Challenge level
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    If two of the sides of a right-angled triangle are 5cm and 6cm long, how many possibilities are there for the length of the third side?
  • Under the Ribbon
    problem

    Under the ribbon

    Age
    14 to 16
    Challenge level
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    A ribbon is nailed down with a small amount of slack. What is the largest cube that can pass under the ribbon ?
  • Tetromino Diagonal
    problem

    Tetromino diagonal

    Age
    14 to 16
    Challenge level
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    Can you calculate the length of this diagonal line?
  • Some(?) of the Parts
    problem

    Some(?) of the parts

    Age
    14 to 16
    Challenge level
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    A circle touches the lines OA, OB and AB where OA and OB are perpendicular. Show that the diameter of the circle is equal to the perimeter of the triangle
  • Get Cross
    problem

    Get cross

    Age
    14 to 16
    Challenge level
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    A white cross is placed symmetrically in a red disc with the central square of side length sqrt 2 and the arms of the cross of length 1 unit. What is the area of the disc still showing?
  • Circle Packing
    problem

    Circle packing

    Age
    14 to 16
    Challenge level
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    Equal circles can be arranged so that each circle touches four or six others. What percentage of the plane is covered by circles in each packing pattern? ...
  • Round and Round
    problem

    Round and round

    Age
    14 to 16
    Challenge level
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    Prove that the shaded area of the semicircle is equal to the area of the inner circle.