挑战习题
1/6单选题
难度:

1.下列关于三角形的内心和外心的说法中,正确的说法为( )
①三角形的内心是三角形内切圆的圆心;
②三角形的内心是三个角平分线的交点;
③三角形的外心到三边的距离相等;
④三角形的外心是三边中垂线的交点.
A ①②③④
B ①②③
C ①②④
D ②③④
提示1:
IOKAnOS4juS4ieinkuW9ouWQhOi+uemDveebuOWIh+eahOWchuWPq+S4ieinkuW9oueahOWGheWIh+Wchu+8jOS4ieinkuW9oueahOWGheWIh+WchueahOWchuW/g+WPq+WBmuS4ieinkuW9oueahOWGheW/g++8jOi/meS4quS4ieinkuW9ouWPq+WBmuWchueahOWkluWIh+S4ieinkuW9oi4g5LiJ6KeS5b2i55qE5YaF5b+D5bCx5piv5LiJ6KeS5b2i5LiJ5Liq5YaF6KeS6KeS5bmz5YiG57q/55qE5Lqk54K5LiDigJ0=
提示2:
IOKAnOS7u+S9leS4gOS4quS4ieinkuW9ouacieS4lOS7heacieS4gOS4quWGheWIh+Wchu+8jOiAjOS7u+S4gOS4quWchumDveacieaXoOaVsOS4quWkluWIh+S4ieinkuW9oi4g4oCd
提示3:
IOKAnOS4ieinkuW9ouWGheW/g+eahOaAp+i0qO+8muS4ieinkuW9oueahOWGheW/g+WIsOS4ieinkuW9ouS4iei+ueeahOi3neemu+ebuOetie+8m+S4ieinkuW9oueahOWGheW/g+S4juS4ieinkuW9oumhtueCueeahOi/nue6v+W5s+WIhui/meS4quWGheinki4g4oCd
正确答案:Qw==
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