I’ve started with a 3x3 square, and divided it into 9 1x1 squares as shown. I’ve added four 1x1 squares such that for each of them one corner lies on a corner of the central 1x1 square, and the corner opposite that lies outside of the 3x3 square. I’ve used this as the basis of the lower figure, a bizarre 20 sided polygon.
What is the perimeter of this polygon?
