英文四邊形數學題(15分)－航空百度

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英文四邊形數學題(15分)

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請依下圖列出所有步驟及理據更新: 圖 http://i246.photobucket.com/albums/gg119/FFS12/ABC22.jpg

最佳解答:

1. PQ//SR (prop. of trapezium) 125 degrees + a = 180 degrees (int. angles, PQ//SR) a = 180 degrees - 125 degrees a = 55 degrees 2. WX//ZY (prop. of trapezium) 2x + 50 degrees = 180 degrees (int. ∠s, WX//ZY) 2x = 180 degrees - 50 degrees x = 130 degrees / 2 x = 65 degrees y + 90 degrees = 180 degrees (int. ∠s, WX//ZY) y = 180 degrees - 90 degrees y = 90 degrees PS. 打唔到角度既符號, 所以用degrees代替

其他解答:

Draw a vertical line PM such that PM⊥RS Then Angle QPM=Angle SMP=90 Angle SPM=125-90=35 So a =180-Angle SMP- Angle SPM =180-90-35 =90-35 =55 (b) y=90 Draw a vertical line XM such that XM⊥YZ Angle WXM=90 Angle YXM=180-90-50=40 Angle X=90+40=130 So x=130/2=65