来自马献阳的问题
如图,⊙O的直径AB与弦CD相交于点M,AE⊥CD于E,BF⊥CD于F.若CM=4,MD=3,BF:AE=1:3,则⊙O的半径是______.
如图,⊙O的直径AB与弦CD相交于点M,AE⊥CD于E,BF⊥CD于F.若CM=4,MD=3,BF:AE=1:3,则⊙O的半径是______.
1回答
2020-06-27 00:27
如图,⊙O的直径AB与弦CD相交于点M,AE⊥CD于E,BF⊥CD于F.若CM=4,MD=3,BF:AE=1:3,则⊙O的半径是______.
如图,⊙O的直径AB与弦CD相交于点M,AE⊥CD于E,BF⊥CD于F.若CM=4,MD=3,BF:AE=1:3,则⊙O的半径是______.
由题意得,AM×MB=CM×MD=12①,
∵AE⊥CD,BF⊥CD,
∴AE∥BF,
∴BM:AM=BF:AE=1:3②,
联合①②可得:AM=6,BM=2,
∴AB=AM+MB=8,
∴⊙O的半径是4.
故答案为:4.