Regular Star Polygons

{10/4}

10/4 reduces to 5/2 by dividing top and bottom by 2, so the {10/4} star consists of two {5/2} stars. The two stars are colored a slightly different shade of blue. The dark blue one has a point pointing up and the light blue one has a point pointing down.

Inside the {10/4} star is a {10/3} star which is colored orange. Since 10 and 3 are relatively prime, the {10/3) star is simple.

Inside the {10/3} star is a {10/2} star which is colored orange. 10/2 reduces to 5 by dividing top and bottom by 2, so the {10/2} star consists of 2 regular pentagons.

Inside the (10/2} star is a yellow {10/1} or regular decagon.