In the figure, ABC is a triangle inscribed
in a circle. If AC = BC = 15cm and AB = 6cm.
(a) find CN.
(Leave your answer in surd form.)
(b) find the radius of the circle.
Figure http://www1.imgload.com/uploads/8260366744.jpg
F4 math problems ( Circles )
2007-03-26 1:54 am
回答 (2)
2007-03-26 2:07 am
✔ 最佳答案
圖片參考：http://www1.imgload.com/uploads/8260366744.jpg
a)
CN = [(AC)^2 - (AN)^2]^0.5 (pyth . theo)
CN = (225 - 9)^0.5
CN = 216^0.5
CN = 6(6)^0.5 cm
b)(CN - r)^2 + AN^2 = OA^2(Pyth.theo)
216 - 12r(6)^1/2 + r^2 + 9 = r^2
r = 7.65 cm
參考: EM
2007-03-26 2:08 am
AN=BN=3
(CB)2=(CN)2+(BN)2
225=(CN)2+9
CN=「216
(CB)2=(CN)2+(BN)2
225=(CN)2+9
CN=「216
參考: Sorry i forget how to culate (b)
收錄日期: 2021-04-13 13:51:32
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https://hk.answers.yahoo.com/question/index?qid=20070325000051KK03714