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.
  • Two Right Angles
    problem

    Two right angles

    Age
    14 to 16
    Challenge level
    filled star filled star empty star
    Weekly Problem 4 - 2008
    In the figure given in the problem, calculate the length of an edge.
  • Strange Rectangle
    problem

    Strange rectangle

    Age
    16 to 18
    Challenge level
    filled star filled star filled star
    ABCD is a rectangle and P, Q, R and S are moveable points on the edges dividing the edges in certain ratios. Strangely PQRS is always a cyclic quadrilateral and you can find the angles.
  • From all corners
    problem

    From all corners

    Age
    14 to 16
    Challenge level
    filled star filled star filled star
    Straight lines are drawn from each corner of a square to the mid points of the opposite sides. Express the area of the octagon that is formed at the centre as a fraction of the area of the square.
  • Flower
    problem

    Flower

    Age
    16 to 18
    Challenge level
    filled star filled star filled star
    Six circles around a central circle make a flower. Watch the flower as you change the radii in this circle packing. Prove that with the given ratios of the radii the petals touch and fit perfectly.
  • 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?
  • Figure of Eight
    problem
    Favourite

    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 ?
  • Von Koch Curve
    problem

    Von Koch curve

    Age
    16 to 18
    Challenge level
    filled star filled star filled star

    Make a poster using equilateral triangles with sides 27, 9, 3 and 1 units assembled as stage 3 of the Von Koch fractal. Investigate areas & lengths when you repeat a process infinitely often.

  • Points in Pairs
    problem

    Points in pairs

    Age
    14 to 16
    Challenge level
    filled star filled star filled star
    Move the point P to see how P' moves. Then use your insights to calculate a missing length.
  • Wedge on Wedge
    problem

    Wedge on wedge

    Age
    14 to 16
    Challenge level
    filled star filled star filled star
    Two right-angled triangles are connected together as part of a structure. An object is dropped from the top of the green triangle where does it pass the base of the blue triangle?