Unified Constructions of the Regular Heptagon and Triskaidecagon

Constructions of regular heptagon and triskaidecagon by trisection of an angle are well known. An elegant construction of the heptagon by S. Adlaj shows a 3-fold symmetry related to a Galois group. Based on the latter construction, in this article one more for the heptagon and two more for the triskaidecagon are presented, all using angle trisection.