问题 选择题
已知ABCDEF是正六边形,且
AB
=
a
AE
=
b
,则
CD
=(  )
A.
1
2
(
a
-
b
)
B.
1
2
(
b
-
a
)
C.
a
+
1
2
b
D.
1
2
(
a
+
b
)
答案

如图,在正六边形ABCDEF中,由正六边形的性质可得

CD
=
1
2
BE
=
1
2
(
AE
-
AB
)
=
1
2
(
b
-
a
)

故选B.

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