Visualising and representing

  • Plus Minus
    problem

    Plus minus

    Age
    14 to 16
    Challenge level
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    Can you explain the surprising results Jo found when she calculated the difference between square numbers?

  • Sitting Pretty
    problem

    Sitting pretty

    Age
    14 to 16
    Challenge level
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    A circle of radius r touches two sides of a right angled triangle, sides x and y, and has its centre on the hypotenuse. Can you prove the formula linking x, y and r?

  • Gnomon dimensions
    problem

    Gnomon dimensions

    Age
    14 to 16
    Challenge level
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    These gnomons appear to have more than a passing connection with the Fibonacci sequence. This problem ask you to investigate some of these connections.
  • Overlap
    problem

    Overlap

    Age
    14 to 16
    Challenge level
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    A red square and a blue square overlap. Is the area of the overlap always the same?

  • In a box
    problem

    In a box

    Age
    14 to 16
    Challenge level
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    Chris and Jo put two red and four blue ribbons in a box. They each pick a ribbon from the box without looking. Jo wins if the two ribbons are the same colour. Is the game fair?

  • Terminology
    problem

    Terminology

    Age
    14 to 16
    Challenge level
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    Given an equilateral triangle inside an isosceles triangle, can you find a relationship between the angles?

  • Pick's Theorem
    problem

    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

    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?

  • Perfectly Square
    problem

    Perfectly square

    Age
    14 to 16
    Challenge level
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    The sums of the squares of three related numbers is also a perfect square - can you explain why?

  • Painted Cube
    problem

    Painted cube

    Age
    14 to 16
    Challenge level
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    Imagine a large cube made from small red cubes being dropped into a pot of yellow paint. How many of the small cubes will have yellow paint on their faces?