Squares

  • Circle Box
    problem

    Circle Box

    Age
    14 to 16
    Challenge level
    2 out of 3

    It is obvious that we can fit four circles of diameter 1 unit in a square of side 2 without overlapping. What is the smallest square into which we can fit 3 circles of diameter 1 unit?

  • Folding Fractions
    problem

    Folding Fractions

    Age
    14 to 16
    Challenge level
    2 out of 3

    What fractions can you divide the diagonal of a square into by simple folding?

  • Small pepper seedlings in turquoise pots.
    problem

    Unusual Polygon

    Age
    14 to 16
    Challenge level
    2 out of 3

    What is the perimeter of this unusually shaped polygon...

  • Similarly so
    problem

    Similarly So

    Age
    14 to 16
    Challenge level
    3 out of 3

    ABCD is a square. P is the midpoint of AB and is joined to C. A line from D perpendicular to PC meets the line at the point Q. Prove AQ = AD.

  • A Tilted Square
    problem

    A Tilted Square

    Age
    14 to 16
    Challenge level
    3 out of 3

    The opposite vertices of a square have coordinates (a,b) and (c,d). What are the coordinates of the other vertices?

  • Trig Rules OK
    problem

    Trig Rules OK

    Age
    16 to 18
    Challenge level
    1 out of 3

    Change the squares in this diagram and spot the property that stays the same for the triangles. Explain...

  • A Swiss sum
    problem

    A Swiss Sum

    Age
    16 to 18
    Challenge level
    1 out of 3

    Can you use the given image to say something about the sum of an infinite series?

  • Zooming in on the Squares
    article

    Zooming in on the Squares

    Start with a large square, join the midpoints of its sides, you'll see four right angled triangles. Remove these triangles, a second square is left. Repeat the operation. What happens?
  • Peg and Pin Boards
    article

    Peg and Pin Boards

    This article for teachers suggests activities based on pegboards, from pattern generation to finding all possible triangles, for example.