Sine, cosine, tangent

  • LOGOSquares
    problem
    Favourite

    Logosquares

    Age
    16 to 18
    Challenge level
    1 out of 3

    Ten squares form regular rings either with adjacent or opposite vertices touching. Calculate the inner and outer radii of the rings that surround the squares.

  • Three by One
    problem
    Favourite

    Three by One

    Age
    16 to 18
    Challenge level
    1 out of 3

    There are many different methods to solve this geometrical problem - how many can you find?

  • Belt
    problem
    Favourite

    Belt

    Age
    16 to 18
    Challenge level
    1 out of 3

    A belt of thin wire, length L, binds together two cylindrical welding rods, whose radii are R and r, by passing all the way around them both. Find L in terms of R and r.

  • Shape and territory
    problem
    Favourite

    Shape and Territory

    Age
    16 to 18
    Challenge level
    2 out of 3

    If for any triangle ABC tan(A - B) + tan(B - C) + tan(C - A) = 0 what can you say about the triangle?

  • So Big
    problem
    Favourite

    So Big

    Age
    16 to 18
    Challenge level
    2 out of 3
    One side of a triangle is divided into segments of length a and b by the inscribed circle, with radius r. Prove that the area is: abr(a+b)/ab-r^2
  • Coke machine
    problem

    Coke Machine

    Age
    14 to 16
    Challenge level
    1 out of 3
    The coke machine in college takes 50 pence pieces. It also takes a certain foreign coin of traditional design...
  • 30-60-90 Polypuzzle
    problem

    30-60-90 Polypuzzle

    Age
    16 to 18
    Challenge level
    1 out of 3
    Re-arrange the pieces of the puzzle to form a rectangle and then to form an equilateral triangle. Calculate the angles and lengths.
  • Sine Problem
    problem

    Sine Problem

    Age
    16 to 18
    Challenge level
    1 out of 3
    In this 'mesh' of sine graphs, one of the graphs is the graph of the sine function. Find the equations of the other graphs to reproduce the pattern.
  • Farhan's Poor Square
    problem

    Farhan's Poor Square

    Age
    14 to 16
    Challenge level
    1 out of 3
    From the measurements and the clue given find the area of the square that is not covered by the triangle and the circle.
  • Small Steps
    problem

    Small Steps

    Age
    16 to 18
    Challenge level
    1 out of 3
    Two problems about infinite processes where smaller and smaller steps are taken and you have to discover what happens in the limit.