问题
选择题
把菱形绕它的中心旋转，使它与原来的菱形重合，那么旋转的角度至少是（ ）
A．90°
B．180°
C．270°
D．360°
答案
∵菱形是中心对称图形，
∴把菱形绕它的中心旋转，使它与原来的菱形重合，旋转角为180°的整数倍，
∴旋转角至少是180°．
故选B．
搜题请搜索小程序“爱下问搜题”
把菱形绕它的中心旋转，使它与原来的菱形重合，那么旋转的角度至少是（ ）
A．90°
B．180°
C．270°
D．360°
∵菱形是中心对称图形，
∴把菱形绕它的中心旋转，使它与原来的菱形重合，旋转角为180°的整数倍，
∴旋转角至少是180°．
故选B．
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