Peter the great accomplished which of the following, which was considered to have the most impact on russia and the policies of his successors?

Peter the great accomplished many things. he brought western influence into Russia. He reduced the influence of Boyars, cut off beards and made them wear clothing that did not cover the legs. He converted to Christianity and the first to bring Russia out of isolation. He traded with other western countries.   

Use the formula: (n-2)×180, where n is the number of sides(18-2)×180= 28800, now this is the full exterior angle of 18-gon so you divide it by 18.28800÷18=160