Harmonic triangles poster Harmonic Triangles Poster Age 14 to 16 Challenge level Exploring and noticing Working systematically Conjecturing and generalising Visualising and representing Reasoning, convincing and proving Being curious Being resourceful Being resilient Being collaborative Problem Problem This poster is based on the problem Harmonic Triangles. The poster is available as a PDF, or the image below can be clicked on to enlarge it. Image