Angles - points, lines and parallel lines

  • Semi-regular Tessellations
    problem
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    Semi-Regular Tessellations

    Age
    11 to 16
    Challenge level
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    Semi-regular tessellations combine two or more different regular polygons to fill the plane. Can you find all the semi-regular tessellations?

  • Same length
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    Same Length

    Age
    11 to 16
    Challenge level
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    Construct two equilateral triangles on a straight line. There are two lengths that look the same - can you prove it?

  • Robotic Rotations
    problem
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    Robotic Rotations

    Age
    11 to 16
    Challenge level
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    How did the the rotation robot make these patterns?

  • Triangle in a Trapezium
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    Triangle in a Trapezium

    Age
    11 to 16
    Challenge level
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    Can you find and prove the relationship between the area of a trapezium and the area of a triangle constructed within it?

  • Using GeoGebra
    article

    Using GeoGebra

    Never used GeoGebra before? This article for complete beginners will help you to get started with this free dynamic geometry software.

  • Making sixty
    problem
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    Making Sixty

    Age
    14 to 16
    Challenge level
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    Why does this fold create an angle of sixty degrees?

  • Isosceles Seven
    problem
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    Isosceles Seven

    Age
    14 to 16
    Challenge level
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    Is it possible to find the angles in this rather special isosceles triangle?

  • A pointed metal arrowhead on the end of an arrow.
    problem

    Arrowhead

    Age
    14 to 16
    Challenge level
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    The points P, Q, R and S are the midpoints of the edges of a non-convex quadrilateral.What do you notice about the quadrilateral PQRS and its area?

  • Hand Swap
    problem

    Hand Swap

    Age
    14 to 16
    Challenge level
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    My train left London between 6 a.m. and 7 a.m. and arrived in Paris between 9 a.m. and 10 a.m. At the start and end of the journey the hands on my watch were in exactly the same positions but the minute hand and hour hand had swopped places. What time did the train leave London and how long did the journey take?