如图1,线段AC=6cm,线段BC=15cm,点M是AC的中点,在CB上取一点N,使得CN:NB=1:2,求M...
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问题详情:
如图1,线段AC=6cm,线段BC=15cm,点M是AC的中点,在CB上取一点N,使得CN:NB=1:2,求MN的长.
【回答】
解:∵M是AC的中点,AC=6,
∴MC=AC=6×=3,·············································································· 1分
又因为CN∶NB=1∶2,BC=15,
∴CN=15×=5,·························································································· 3分
∴MN=MC+CN=3+5=8,
∴MN的长为8 cm·························································································· 4分
知识点:直*、*线、线段
题型:解答题