Three points A, B and C lie in this order on a line, and P is any
point in the plane. Use the Cosine Rule to prove the following
Figure of Eight
Age 14 to 16 Challenge Level
Identify why the yellow and green triangles are similar and then try to work out the line ratio. You'll need to think about the angles made to the centre of the pegboard.
How is the area ratio connected to the line ratio?
The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the
NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to
embed rich mathematical tasks into everyday classroom practice.