若△ABC的周长为l，两条内角平分线的交点到一边的距离为r，那么△ABC的面积为（）-九年级数学

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• 如图所示，四边形ABCD为一正方形，E、F分别为BC、CD的中点，对角线AC与BD相交于O点，且AE与OB相交于G点，AF与OD相交于H点，下列说法正确的有①E点是线段BC的重心；②G点是△ABC-八
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• 如图，⊙O是△ABC的内切圆，与边BC，CA，AB的切点分别为D，E，F，若∠A=70°，则∠EDF=（）度．-九年级数学
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• （1）已知点G是△ABC的重心，AG=6，那么DG=___，点G与边BC中点之间的距离是____；（2）△ABC的面积为9cm2，则△ABG的面积为___cm2。（3）连接CG，若AG⊥GC，AC=4
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