Sine, cosine, tangent

  • Bend
    problem

    Bend

    Age
    16 to 18
    Challenge level
    filled star empty star empty star
    What is the longest stick that can be carried horizontally along a narrow corridor and around a right-angled bend?
  • Diagonals for Area
    problem

    Diagonals for Area

    Age
    16 to 18
    Challenge level
    filled star filled star empty star
    Can you prove this formula for finding the area of a quadrilateral from its diagonals?
  • Screen Shot
    problem

    Screen Shot

    Age
    14 to 16
    Challenge level
    filled star filled star empty star
    A moveable screen slides along a mirrored corridor towards a centrally placed light source. A ray of light from that source is directed towards a wall of the corridor, which it strikes at 45 degrees before being reflected across to the opposite wall and so on until it hits the screen.
  • Sine and Cosine for Connected Angles
    problem

    Sine and Cosine for Connected Angles

    Age
    14 to 16
    Challenge level
    filled star filled star empty star
    The length AM can be calculated using trigonometry in two different ways. Create this pair of equivalent calculations for different peg boards, notice a general result, and account for it.
  • Flight Path
    problem

    Flight Path

    Age
    16 to 18
    Challenge level
    filled star filled star empty star
    Use simple trigonometry to calculate the distance along the flight path from London to Sydney.
  • Raising The Roof
    problem

    Raising the Roof

    Age
    14 to 16
    Challenge level
    filled star filled star empty star
    How far should the roof overhang to shade windows from the mid-day sun?
  • Pumping the Power
    problem

    Pumping the Power

    Age
    16 to 18
    Challenge level
    filled star filled star empty star
    What is an AC voltage? How much power does an AC power source supply?
  • At a glance
    problem

    At a Glance

    Age
    14 to 16
    Challenge level
    filled star filled star filled star
    The area of a regular pentagon looks about twice as a big as the pentangle star drawn within it. Is it?
  • Circumnavigation
    problem

    Circumnavigation

    Age
    14 to 16
    Challenge level
    filled star filled star filled star
    The sides of a triangle are 25, 39 and 40 units of length. Find the diameter of the circumscribed circle.
  • Circle Scaling
    problem

    Circle Scaling

    Age
    14 to 16
    Challenge level
    filled star filled star filled star
    Describe how to construct three circles which have areas in the ratio 1:2:3.