The Rhubarb Triangle

I stole the concept from Matthew' mum.
Quiet day at home. Work rate hindered by slow running technology. When will I finish these lecture handouts? No time soon at this rate.
NB the rhubarb triangle is a part of West Yorkshire famous for its weird and wonderful way of growing this delicacy. My great grandparents were rhubarb growers. I'm reduced to knitting it!