#regular_polygon  a polygon with all sides and all angles equal
  supertype:  #polygon__polygonal_shape__polygonalshape  a closed plane figure bounded by straight sides
  subtype:  #equilateral_triangle__equilateraltriangle__equiangular_triangle__equiangulartriangle  a three-sided regular polygon

No statement uses or specializes #regular_polygon; click here to add one.