如图,在△ABC中,角C=90°,AC=16cm,AB的垂直平分线MN交AC于D,交AB于点E,连接BD,若CD:DB=3:5,求CD的长.图片:file:///C:/Documents%20and%20Settings/Administrator/Application%20Data/360se/ie8data/Temporary%20Internet%20Files/Content.IE

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如图,在△ABC中,角C=90°,AC=16cm,AB的垂直平分线MN交AC于D,交AB于点E,连接BD,若CD:DB=3:5,求CD的长.图片:file:///C:/Documents%20and%20Settings/Administrator/Application%20Data/360se/ie8data/Temporary%20Internet%20Files/Content.IE
如图,在△ABC中,角C=90°,AC=16cm,AB的垂直平分线MN交AC于D,交AB于点E,连接BD,若CD:DB=3:5,求CD的长.
图片:file:///C:/Documents%20and%20Settings/Administrator/Application%20Data/360se/ie8data/Temporary%20Internet%20Files/Content.IE5/U383432F/2c5f6a21[1].png

如图,在△ABC中,角C=90°,AC=16cm,AB的垂直平分线MN交AC于D,交AB于点E,连接BD,若CD:DB=3:5,求CD的长.图片:file:///C:/Documents%20and%20Settings/Administrator/Application%20Data/360se/ie8data/Temporary%20Internet%20Files/Content.IE
设BD长为5X则
CD长3x所以BC长为4X
因为DE是AB的垂直平分线
所以BD=AD=5X
所以AC=AD+CD=8X=16cm
所以X=2cm
所以CD=6cm