Similarity and congruence

  • Squareflake
    problem

    Squareflake

    Age
    16 to 18
    Challenge level
    filled star filled star empty star
    A finite area inside and infinite skin! You can paint the interior of this fractal with a small tin of paint but you could never get enough paint to paint the edge.
  • Sierpinski Triangle
    problem

    Sierpinski triangle

    Age
    16 to 18
    Challenge level
    filled star filled star empty star
    What is the total area of the triangles remaining in the nth stage of constructing a Sierpinski Triangle? Work out the dimension of this fractal.
  • Guillotine
    problem

    Guillotine

    Age
    11 to 14
    Challenge level
    filled star filled star empty star
    Weekly Problem 9 - 2006
    What fraction of the area of the rectangle is shaded?
  • Triangle in a Triangle
    problem

    Triangle in a triangle

    Age
    14 to 16
    Challenge level
    filled star filled star empty star

    Can you work out the fraction of the original triangle that is covered by the inner triangle?

  • Figure of Eight
    problem

    Figure of eight

    Age
    14 to 16
    Challenge level
    filled star filled star filled star
    On a nine-point pegboard a band is stretched over 4 pegs in a "figure of 8" arrangement. How many different "figure of 8" arrangements can be made ?
  • Pentabuild
    problem

    Pentabuild

    Age
    16 to 18
    Challenge level
    filled star filled star empty star
    Explain how to construct a regular pentagon accurately using a straight edge and compass.
  • Slippage
    problem

    Slippage

    Age
    14 to 16
    Challenge level
    filled star filled star empty star
    A ladder 3m long rests against a wall with one end a short distance from its base. Between the wall and the base of a ladder is a garden storage box 1m tall and 1m high. What is the maximum distance up the wall which the ladder can reach?
  • Bus Stop
    problem

    Bus stop

    Age
    14 to 16
    Challenge level
    filled star filled star filled star
    Two buses leave at the same time from two towns Shipton and Veston on the same long road, travelling towards each other. At each mile along the road are milestones. The buses' speeds are constant and in the ratio 5 to 4. The buses travel to and fro between the towns. What milestones are at Shipton and Veston?
  • All Tied Up
    problem

    All tied up

    Age
    14 to 16
    Challenge level
    filled star filled star empty star
    A ribbon runs around a box so that it makes a complete loop with two parallel pieces of ribbon on the top. How long will the ribbon be?
  • Squirty
    problem

    Squirty

    Age
    14 to 16
    Challenge level
    filled star filled star filled star

    Using a ruler, pencil and compasses only, it is possible to construct a square inside any triangle so that all four vertices touch the sides of the triangle.