Area - circles, sectors and segments

  • Blue and White
    problem

    Blue and white

    Age
    11 to 14
    Challenge level
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    Identical squares of side one unit contain some circles shaded blue. In which of the four examples is the shaded area greatest?

  • An Unusual Shape
    problem

    An unusual shape

    Age
    11 to 14
    Challenge level
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    Can you maximise the area available to a grazing goat?

  • problem

    Salinon

    Age
    14 to 16
    Challenge level
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    This shape comprises four semi-circles. What is the relationship between the area of the shaded region and the area of the circle on AB as diameter?

  • Efficient packing
    problem

    Efficient packing

    Age
    14 to 16
    Challenge level
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    How efficiently can you pack together disks?
  • Curvy areas
    problem

    Curvy areas

    Age
    14 to 16
    Challenge level
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    Have a go at creating these images based on circles. What do you notice about the areas of the different sections?

  • Geometry and Measure - Short Problems
    problem

    F'arc'tion

    Age
    14 to 16
    Challenge level
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    At the corner of the cube circular arcs are drawn and the area enclosed shaded. What fraction of the surface area of the cube is shaded? Try working out the answer without recourse to pencil and paper.

  • 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?

  • Gutter
    problem

    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?

  • Giant Holly Leaf
    problem

    Giant holly leaf

    Age
    14 to 16
    Challenge level
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    Find the perimeter and area of a holly leaf that will not lie flat (it has negative curvature with 'circles' having circumference greater than 2πr).
  • Compare Areas
    problem

    Compare areas

    Age
    14 to 16
    Challenge level
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    Which has the greatest area, a circle or a square, inscribed in an isosceles right angle triangle?