Regular heptagon: join every two and every three vertexes.

Regular Hexagon: it doesn’t have a proper star polygon, but we can draw a star with one equilateral triangle and another one inverted).

Regular pentagon(Join every two vertexes).

STAR POLYGONS

Nonagon: join every two and four vertexes.

Hendecagon: join every two and five vertexes

Join every three vertexes.Regular octagon:

STAR POLYGONS

Decagon: join every three and four vertexes.