将下面两个图形重叠后,会变成()。
A:
B:
C:
D:
如图,把一个矩形纸片ABCD沿AD和BC的中点连线EF对折,要使矩形AEFB与原矩形相似,则原矩形长与宽的比为( )
(Ⅰ)求tanα的值;
(Ⅱ)求 2sin2α+sin2α1+tanα 的值.
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