Being curious

  • Triangle midpoints
    problem
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    Triangle Midpoints

    Age
    14 to 16
    Challenge level
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    You are only given the three midpoints of the sides of a triangle. How can you construct the original triangle?

  • Five green equilateral triangles, arranged to almost make a complete pentagon.
    problem
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    Doesn't Add Up

    Age
    14 to 16
    Challenge level
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    In this problem we are faced with an apparently easy area problem, but it has gone horribly wrong! What happened?

  • Expenses
    problem
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    Expenses

    Age
    14 to 16
    Challenge level
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    What is the largest number which, when divided into these five numbers in turn, leaves the same remainder each time?

  • Fair Shares?
    problem
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    Fair Shares?

    Age
    14 to 16
    Challenge level
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    A mother wants to share some money by giving each child in turn a lump sum plus a fraction of the remainder. How can she do this to share the money out equally?

  • What's Possible?
    problem
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    What's Possible?

    Age
    14 to 16
    Challenge level
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    Many numbers can be expressed as the difference of two perfect squares. What do you notice about the numbers you CANNOT make?

  • Why 24?
    problem
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    Why 24?

    Age
    14 to 16
    Challenge level
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    Take any prime number greater than 3 , square it and subtract one. Working on the building blocks will help you to explain what is special about your results.

  • Arclets
    problem
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    Arclets

    Age
    14 to 16
    Challenge level
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    Each of the following shapes is made from arcs of a circle of radius r. What is the perimeter of a shape with 3, 4, 5 and n "nodes".

  • Semi-detached
    problem
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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.

  • Pick's Theorem
    problem
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    Pick's Theorem

    Age
    14 to 16
    Challenge level
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    Polygons drawn on square dotty paper have dots on their perimeter (p) and often internal (i) ones as well. Find a relationship between p, i and the area of the polygons.

  • problem
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    Triangles and Petals

    Age
    14 to 16
    Challenge level
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    An equilateral triangle rotates around regular polygons and produces an outline like a flower. What are the perimeters of the different flowers?