Ratio and proportion

  • Same Height
    problem

    Same Height

    Age
    14 to 16
    Challenge level
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    A trapezium is divided into four triangles by its diagonals. Can you work out the area of the trapezium?

  • Televisual Technology
    problem

    Televisual Technology

    Age
    14 to 16
    Challenge level
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    If a new and an old television have screens of the same area, what is the ratio of their widths?

  • Orbiting Billiard Balls
    problem

    Orbiting Billiard Balls

    Age
    14 to 16
    Challenge level
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    What angle is needed for a ball to do a circuit of the billiard table and then pass through its original position?

  • The Rescaled Map
    problem

    The Rescaled Map

    Age
    14 to 16
    Challenge level
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    We use statistics to give ourselves an informed view on a subject of interest. This problem explores how to scale countries on a map to represent characteristics other than land area.

  • Points in Pairs
    problem

    Points in Pairs

    Age
    14 to 16
    Challenge level
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    Move the point P to see how P' moves. Then use your insights to calculate a missing length.

  • Wedge on Wedge
    problem

    Wedge on Wedge

    Age
    14 to 16
    Challenge level
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    Two right-angled triangles are connected together as part of a structure. An object is dropped from the top of the green triangle where does it pass the base of the blue triangle?

  • Dilution series calculator
    problem

    Dilution Series Calculator

    Age
    14 to 16
    Challenge level
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    Which dilutions can you make using 10ml pipettes and 100ml measuring cylinders?

  • Pent
    problem

    Pent

    Age
    14 to 18
    Challenge level
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    The diagram shows a regular pentagon with sides of unit length. Find all the angles in the diagram. Prove that the quadrilateral shown in red is a rhombus.

  • Napoleon's Hat
    problem

    Napoleon's Hat

    Age
    16 to 18
    Challenge level
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    Three equilateral triangles ABC, AYX and XZB are drawn with the point X a moveable point on AB. The points P, Q and R are the centres of the three triangles. What can you say about triangle PQR?