1)
http://i729.photobucket.com/albums/ww291/kaka1307/DSC00530.jpg
two circles meet at A & C.ABK is a straight line and angle ABC=130.
Find
a)angle AOC
b)angle CKB
2) http://i729.photobucket.com/albums/ww291/kaka1307/DSC00531.jpg
CB is the diameter of the circle CBD,CBA and CDE are straight lines.
If angle BCD=35,find angle AEC.
pls show steps.thz!
f.4 circle
2010-05-14 1:27 am
回答 (1)
2010-05-14 1:43 am
✔ 最佳答案
1)a)360 - ㄥAOC = 2ㄥABC (圓心角兩倍於圓周角)
360 - ㄥAOC = 2 * 130
ㄥAOC = 100°
b)
ㄥAOC + ㄥCKB = 180 (圓內接4邊形對角互補)
100 + ㄥCKB = 180
ㄥCKB = 80°
2)
Join BD ,
ㄥABC = ㄥCBD (圓內接4邊形對角之補角)
ㄥBDC = 90° (半圓所對圓周角)
So
ㄥABC
= ㄥCBD
= 180 - 35 - ㄥBDC
= 180 - 35 - 90
= 55°
2010-05-13 18:11:53 補充：
003
H ( 小學級 3 級 ) 抄答案!!
立即檢舉!!!!
收錄日期: 2021-04-21 22:11:52
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100513000051KK00821