Area - triangles, quadrilaterals, compound shapes

  • Inscribed in a Circle
    problem
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    Inscribed in a circle

    Age
    14 to 16
    Challenge level
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    The area of a square inscribed in a circle with a unit radius is 2. What is the area of these other regular polygons inscribed in a circle with a unit radius?

  • Areas of parallelograms
    problem
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    Areas of parallelograms

    Age
    14 to 16
    Challenge level
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    Can you find the area of a parallelogram defined by two vectors?

  • Trapezium Four
    problem
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    Trapezium four

    Age
    14 to 16
    Challenge level
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    The diagonals of a trapezium divide it into four parts. Can you create a trapezium where three of those parts are equal in area?

  • Gutter
    problem
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    Gutter

    Age
    14 to 16
    Challenge level
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    Manufacturers need to minimise the amount of material used to make their product. What is the best cross-section for a gutter?

  • Towering Trapeziums
    problem

    Towering trapeziums

    Age
    14 to 16
    Challenge level
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    Can you find the areas of the trapezia in this sequence?
  • Six Discs
    problem

    Six discs

    Age
    14 to 16
    Challenge level
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    Six circular discs are packed in different-shaped boxes so that the discs touch their neighbours and the sides of the box. Can you put the boxes in order according to the areas of their bases?
  • Bicentric Quadrilaterals
    problem

    Bicentric quadrilaterals

    Age
    14 to 16
    Challenge level
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    Investigate the properties of quadrilaterals which can be drawn with a circle just touching each side and another circle just touching each vertex.
  • Trapezium made of wooden tangram pieces, including a square and a parallelogram.
    problem
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    Quad in quad

    Age
    14 to 18
    Challenge level
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    Join the midpoints of a quadrilateral to get a new quadrilateral. What is special about it?

  • Kite in a Square
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    Kite in a square

    Age
    14 to 18
    Challenge level
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    Can you make sense of the three methods to work out what fraction of the total area is shaded?

  • Halving the Triangle
    problem

    Halving the triangle

    Age
    16 to 18
    Challenge level
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    Draw any triangle PQR. Find points A, B and C, one on each side of the triangle, such that the area of triangle ABC is a given fraction of the area of triangle PQR.