This is based on one of our favourite designs called From Square to Eternity.¹ This is only half of that design so becomes Halfway to Paradise.

It begins with the small triangle in the centre and all the other triangles are added according to the rules of Pythagoras Theorem. Once you have picked up the stitches for a shape you immediately start decreasing. Each row has fewer stitches than the row before so it seems as though the work grows very quickly.

The original shawl has now been lost so there are no good photos. I believe I used Jonelle Kid Mohair and used five balls of grey and three of black. I worked at a gauge of 14 stitches to 10 cm to make it very light and airy.

The pattern is also available in Mufflermatics an ebook of mathematical scarves and shawls.