A regular decagon and triangles from vertices and side midpoints. What fraction is red?
Categories
Bandaged head
Tag: decagon
Categories
The pentangle flower
Multicoloured pentangle in a red circle. Rhombuses form two levels of petals growing outward, forming a decagon. Show that the opposite sides of the two interleaved pentagons are equal in pairs and also equal and parallel to the sides of the pentangle.