Triangles

  • Name That Triangle!
    problem
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    Name That Triangle!

    Age
    7 to 11
    Challenge level
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    Can you sketch triangles that fit in the cells in this grid? Which ones are impossible? How do you know?

  • Egyptian Rope
    problem
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    Egyptian Rope

    Age
    7 to 11
    Challenge level
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    The ancient Egyptians were said to make right-angled triangles using a rope with twelve equal sections divided by knots. What other triangles could you make if you had a rope like this?

  • More Transformations on a Pegboard
    problem
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    More Transformations on a Pegboard

    Age
    7 to 11
    Challenge level
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    Use the interactivity to find all the different right-angled triangles you can make by just moving one corner of the starting triangle.

  • Overlaps
    problem
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    Overlaps

    Age
    7 to 11
    Challenge level
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    What does the overlap of these two shapes look like? Try picturing it in your head and then use some cut-out shapes to test your prediction.

  • problem
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    Cut It Out

    Age
    7 to 11
    Challenge level
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    Can you dissect an equilateral triangle into 6 smaller ones? What number of smaller equilateral triangles is it NOT possible to dissect a larger equilateral triangle into?

  • Triangles all Around
    problem
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    Triangles All Around

    Age
    7 to 11
    Challenge level
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    Can you find all the different triangles on these peg boards, and find their angles?

  • Fraction Fascination
    problem
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    Fraction Fascination

    Age
    7 to 11
    Challenge level
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    This problem challenges you to work out what fraction of the whole area of these pictures is taken up by various shapes.

  • Tilted Squares
    problem
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    Tilted Squares

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

  • Isosceles Triangles
    problem
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    Isosceles Triangles

    Age
    11 to 14
    Challenge level
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    Draw some isosceles triangles with an area of $9cm^2$ and a vertex at (20,20). If all the vertices must have whole number coordinates, how many is it possible to draw?

  • Constructing Triangles
    problem
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    Constructing Triangles

    Age
    11 to 14
    Challenge level
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    Generate three random numbers to determine the side lengths of a triangle. What triangles can you draw?