1.if an interior angle of a regular polygon is 5 times its exterior angle,find the number of sides of the regular polygon
2.if twice of an exterior angle of a regular polygon is 140 less than its interior angle,find the number of sides of the regular polygon
f.2簡單polygon
2010-05-18 2:53 am
回答 (1)
2010-05-18 3:39 am
✔ 最佳答案
1. An interior angle = (n - 2)(180*)/nAn exterior angle = 360*/n
So, (n - 2)(180*)/n = 5(360*)/n
(n - 2) = 10
n = 12
So, the regular polygon is a 12-side polygon
2. 2(360*)/n + 140* = (n - 2)(180*)/n
720* + n140* = n180* - 360*
40*n = 1080*
n = 27
So, the number of sides of the regular polygon is 27
參考: Prof. Physics
收錄日期: 2021-04-19 22:14:03
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100517000051KK01059