英文等腰三角形數學題3(15分)

👨🏻‍🏫 學術台數學

mary

2008-12-02 12:38 am

觀看下圖,請以英文寫出所有解釋,如(angle sum of triangle)等
http://i246.photobucket.com/albums/gg119/FFS12/TRI3.jpg

回答 (2)

Jacob

2008-12-02 2:43 am

✔ 最佳答案

Let ∠CBD=∠ABD=α

Since AB=AC (given), we have
∠ABC=∠ACB=2α (base ∠, isos.Δ)

Finally ∠ADB=∠CBD+∠ACB (ext. ∠ of Δ)
and so ∠ADB=3α=3∠CBD

參考: ME

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[匿名]

2008-12-02 1:26 am

<ACB = <ABC = 2<CBD(BASE ANGLE ISOS TRIANGLE

<ADB = <CBD + <ACB (Angle sum og triangle)

So <ADB = 3<CBD

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