Quadrilaterals

  • Cyclic Quad Jigsaw
    problem

    Cyclic Quad Jigsaw

    Age
    14 to 16
    Challenge level
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    A picture is made by joining five small quadrilaterals together to make a large quadrilateral. Is it possible to draw a similar picture if all the small quadrilaterals are cyclic?
  • 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.
  • Square Pair
    problem

    Square Pair

    Age
    14 to 18
    Challenge level
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    Explore the shape of a square after it is transformed by the action of a matrix.

  • Set Square
    problem

    Set Square

    Age
    16 to 18
    Challenge level
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    A triangle PQR, right angled at P, slides on a horizontal floor with Q and R in contact with perpendicular walls. What is the locus of P?

  • The Cyclic Quadrilateral
    article

    The Cyclic Quadrilateral

    This gives a short summary of the properties and theorems of cyclic quadrilaterals and links to some practical examples to be found elsewhere on the site.