Pythagoras' theorem

  • Round and Round
    problem

    Round and Round

    Age
    14 to 16
    Challenge level
    2 out of 3

    Prove that the shaded area of the semicircle is equal to the area of the inner circle.

  • Grid lockout
    problem

    Grid Lockout

    Age
    14 to 16
    Challenge level
    2 out of 3
    What remainders do you get when square numbers are divided by 4?
  • Rhombus in Rectangle
    problem

    Rhombus in Rectangle

    Age
    14 to 16
    Challenge level
    2 out of 3

    Take any rectangle ABCD such that AB > BC. The point P is on AB and Q is on CD. Show that there is exactly one position of P and Q such that APCQ is a rhombus.

  • Matter of Scale
    problem

    Matter of Scale

    Age
    14 to 16
    Challenge level
    2 out of 3

    Can you prove Pythagoras' Theorem using enlargements and scale factors?

  • Corridors
    problem

    Corridors

    Age
    14 to 16
    Challenge level
    2 out of 3

    A 10×10×10 cube is made from 27 2×2 cubes with corridors between them. Find the shortest route from one corner to the opposite corner.

  • 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?

  • Small pepper seedlings in turquoise pots.
    problem

    Folded Over

    Age
    14 to 16
    Challenge level
    2 out of 3

    A rectangular piece of paper is folded. Can you work out one of the lengths in the diagram?

  • Small pepper seedlings in turquoise pots.
    problem

    Walk the Plank

    Age
    14 to 16
    Challenge level
    2 out of 3

    A rectangular plank fits neatly inside a square frame when placed diagonally. What is the length of the plank?

  • The Fire-fighter's Car Keys
    problem

    The Fire-Fighter's Car Keys

    Age
    14 to 16
    Challenge level
    2 out of 3

    A fire-fighter needs to fill a bucket of water from the river and take it to a fire. What is the best point on the river bank for the fire-fighter to fill the bucket?

  • Small pepper seedlings in turquoise pots.
    problem

    Folding in Half

    Age
    14 to 16
    Challenge level
    2 out of 3

    How does the perimeter change when we fold this isosceles triangle in half?