1.Find the area of the equilateral triangle whose side length is x.
2.Find the side length of the equilateral triangle whose area is √3 cm^2
http://www.justyoulike.com/images/1242556771x983044760.jpg
簡單中二數學問題(英文)
2009-05-18 2:38 am
回答 (1)
2009-05-18 2:50 am
✔ 最佳答案
1)With reference to your figure ,
Let AD丄BC
In tri ADC ,
cos60=DC/x
DC=cos60*x=(x/2)
The area of the tri .
=(1/2)(DC)(AC)sin60
=(1/2)(x/2)(x)(√3/2)
=(√3/8)x^2 sq unit
2)
By the result of (1)
(√3/8)x^2=√3
x^2=8
x=2√2 cm
收錄日期: 2021-04-22 00:40:53
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https://hk.answers.yahoo.com/question/index?qid=20090517000051KK01668