Question

英文版初一数学题，题目是用英文写的，其实很简单

Each exterior angle of a regular polygon of n sides is 16 degree greater than each exterior angle of another regular polygon of 3n sides.
(a) Form an equation in n and solve for the value of n
(b) Calculate the interior angle of the regular polygon of 3n sides

Answer 1

正n边形的每个外角比正3n边形的每个外角大16°，（a）求n满足的方程并解出n（b）计算正3n边形的内角。
解：
n多边形的外角和：360°，所以正n边形的每个外角：360°/n,正3n边形的每个外角：120°/n于是有
360°/n=120°/n+16°，也即：16n=240，解得n=15
正45边形的外角为：8°，所以内角为172°

Answer 2

n＝15，the interior angle of the regular polygon of 3n sides＝172度