A如图,在直角三角形ABC中,∠ACB=90°,CD是B边上的高,AB=13cm,BC=12cm,AC=5cm.求(1)△ABC的面积;(2)CD的长
解答历碧:⑴由S=½仔歼AC×BC=½×5×12=30┩²,⑵由面积相等得:肢戚举½AB×CD=30得:CD=60/13
(1)S△ABC=1/2ACXBC=30
(2)S△ABC=1/漏仔派2AC×BC=1/2AB×CD=30,戚培∴返贺CD=30÷(1/2AB)=60/13≈4.62
(1)S=30 , (2)CD=60/13
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