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Is there a term for the shape shown above: a smooth, continuous curve with three axes of symmetry? And if anyone could share the equation for this curve, I would be very grateful. (continued)

Keith Parkin
Sheffield, UK

I don’t know the equation nor the name (my Greek being insufficient) of the curve required. However, I can offer a relatively simple way to draw such a shape using a straight edge and compass.

Take an equilateral triangle and extend its sides out across the page. Now, draw an arc centred on a corner of your choice, connecting the two lines…