Triangles

  • Cartesian Isometric
    problem

    Cartesian Isometric

    Age
    7 to 11
    Challenge level
    3 out of 3
    The graph below is an oblique coordinate system based on 60 degree angles. It was drawn on isometric paper. What kinds of triangles do these points form?
  • Triangle Pin-Down
    problem

    Triangle Pin-Down

    Age
    7 to 11
    Challenge level
    3 out of 3

    Use the interactivity to investigate what kinds of triangles can be drawn on peg boards with different numbers of pegs.

  • Sticks and Triangles
    problem

    Sticks and Triangles

    Age
    7 to 11
    Challenge level
    3 out of 3
    Using different numbers of sticks, how many different triangles are you able to make? Can you make any rules about the numbers of sticks that make the most triangles?
  • Triangle transformation
    problem

    Triangle Transformation

    Age
    7 to 14
    Challenge level
    1 out of 3
    Start with a triangle. Can you cut it up to make a rectangle?
  • Threesomes
    problem

    Threesomes

    Age
    11 to 14
    Challenge level
    1 out of 3

    Imagine an infinitely large sheet of square dotty paper on which you can draw triangles of any size you wish (providing each vertex is on a dot). What areas is it/is it not possible to draw?

  • Dotty triangles
    problem

    Dotty Triangles

    Age
    11 to 14
    Challenge level
    1 out of 3

    Imagine an infinitely large sheet of square dotty paper on which you can draw triangles of any size you wish (providing each vertex is on a dot). What areas is it/is it not possible to draw?

  • Small pepper seedlings in turquoise pots.
    problem

    Isosceles Meld

    Age
    11 to 14
    Challenge level
    1 out of 3

    Weekly Problem 9 - 2012
    What is the angle QPT in this diagram?

  • Small pepper seedlings in turquoise pots.
    problem

    Stellar Angles

    Age
    11 to 14
    Challenge level
    1 out of 3

    Weekly Problem 30 - 2013
    What is the angle $x$ in the star shape shown?

  • Notes on a triangle
    problem

    Notes on a Triangle

    Age
    11 to 14
    Challenge level
    1 out of 3
    Can you describe what happens in this film?
  • Triangular Tantaliser
    problem

    Triangular Tantaliser

    Age
    11 to 14
    Challenge level
    2 out of 3

    Draw all the possible distinct triangles on a 4 × 4 dotty grid. Convince me that you have all possible triangles.