1. In the figure, AB, BC and CD are three sides of a regular polygon where ∠BAC = 12∘.
(a) Find the size of an exterior angle of the regular polygon.
(b) Find the number of sides of the regular polygon.
figure: http://imgur.com/noERH0p
2. In Fig. (1), ABCDEFGH is a regular octagon.
(a) Find x.
(b) Hence, find y in the Fig. (2)
figure: http://imgur.com/qURen9R
F.2 數學題 (2)
2014-11-21 3:53 am
回答 (1)
2014-11-21 6:58 am
✔ 最佳答案
1.
(a)
Since the triangle shown is an isosceles triangle with each of the two baseangles of 12°,
thus the interior angle of the regular polygon
= 12° x 2
= 24°
(b)
The number of sides of the regular polygon
= 360°/24°
= 15
====
2.
(a)
x is the interior angle of a regular octagon.
Hence, x
= (2 × 8 - 4) × 90° / 8
= 135°
(b)
y is also the interior angle of a regular octagon.
Hence, y
= 135°
2014-11-20 22:59:36 補充：
The answer of 1. (b) is 15°
收錄日期: 2021-04-15 17:15:31
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20141120000051KK00093