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Hilda
Joined: 15 Apr 2004Posts: 12

Posted: Thu Apr 15, 2004 10:46 pm Post subject: 求BC和 S△ABC.



在△ABC中，AB=2√3，∠A=45°，∠B=60°，求BC和 S△ABC.





me
Frequent VisitorJoined: 12 Feb 2004Posts: 213
Location: Hong Kong

Posted: Thu Apr 15, 2004 11:27 pm Post subject: Re: 求BC和 S△ABC.



Hilda wrote:

在△ABC中，AB=2√3，∠A=45°，∠B=60°，求BC和 S△ABC. 
AB/sinC=BC/sinA, so we can find BC. area of ABC=1/2(AB)(BC)sinB, so we can find it.
Another way is to drop a from A or B or C to the opposite side.





Hilda
Joined: 15 Apr 2004Posts: 12

Posted: Fri Apr 16, 2004 10:16 pm Post subject: Re: 求BC和 S△ABC.



me wrote:

Hilda wrote:

在△ABC中，AB=2√3，∠A=45°，∠B=60°，求BC和 S△ABC. 
AB/sinC=BC/sinA, so we can find BC. area of ABC=1/2(AB)(BC)sinB, so we can find it.
Another way is to drop a from A or B or C to the opposite side.

AB/sinC=BC/sinA中的sinC同sinA點求呀?比得AB=2√3一個值咋喎?





Ellen
Frequent VisitorJoined: 28 Oct 2003Posts: 212
Location: CUHK

Posted: Fri Apr 16, 2004 11:24 pm Post subject:



so
and the easiset way you can find sinC is using a calculator to find [/tex]





Hilda
Joined: 15 Apr 2004Posts: 12

Posted: Fri Apr 16, 2004 11:30 pm Post subject:



咁點解係AB/sinC=BC/sinA?





Soarer
Frequent VisitorJoined: 18 Jan 2004Posts: 213
Location: Hong Kong

Posted: Fri Apr 16, 2004 11:55 pm Post subject:



Hilda wrote:

咁點解係AB/sinC=BC/sinA? 
請問你幾年級?





Hilda
Joined: 15 Apr 2004Posts: 12

Posted: Fri Apr 16, 2004 11:59 pm Post subject:



Soarer wrote:

Hilda wrote:

咁點解係AB/sinC=BC/sinA? 
請問你幾年級?

中三~咁你呢?





me
Frequent VisitorJoined: 12 Feb 2004Posts: 213
Location: Hong Kong

Posted: Sat Apr 17, 2004 2:12 am Post subject:



Hilda wrote:

Soarer wrote:

Hilda wrote:

咁點解係AB/sinC=BC/sinA? 
請問你幾年級?

中三~咁你呢?

Soarer is f.5.





newb1e
Joined: 05 Apr 2004Posts: 11





Hilda
Joined: 15 Apr 2004Posts: 12

Posted: Sat Apr 17, 2004 2:17 pm Post subject:



唔該晒以上解答過我問題既人!!!





