Four rods are hinged at their ends to form a convex quadrilateral.
Investigate the different shapes that the quadrilateral can take.
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A hexagon, with sides alternately a and b units in length, is
inscribed in a circle. How big is the radius of the circle?
NRICH has always had good solutions from Madras College in St
Andrew's, Scotland but the solutions to this problem were truly
An observer is on top of a lighthouse. How far from the foot of the lighthouse is the horizon that the observer can see?
Stick some cubes together to make a cuboid. Find two of the angles
by as many different methods as you can devise.
What angle is needed for a ball to do a circuit of the billiard
table and then pass through its original position?
An environment that simulates a protractor carrying a right- angled
triangle of unit hypotenuse.
A dot starts at the point (1,0) and turns anticlockwise. Can you
estimate the height of the dot after it has turned through 45
degrees? Can you calculate its height?
A collection of short Stage 4 problems on trigonometry.