周长相等时，以下哪种图形的面积最大？ 正方形，长方形,菱形,平行四边形 当周长相等时，面积最大的是（ ） A．平行四边形 ...
\u9009\u62e9\u9898 :\u5f53\u4e0b\u9762\u56fe\u5f62\u7684\u5468\u957f\u76f8\u7b49\u65f6\uff0c\u54ea\u4e2a\u56fe\u5f62\u7684\u9762\u79ef\u6700\u5927\uff1fA \u957f\u65b9\u5f62 B \u6b63\u65b9\u5f62 C \u5e73\u884c\u56db\u8fb9\u5f62 \u4e3a\u4ec0\u4e48\uff1fB
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\u6839\u636e\u5e73\u884c\u56db\u8fb9\u5f62\u9762\u79ef\u63a8\u5bfc\u516c\u5f0f\u53ef\u77e5\uff0c\u5468\u957f\u76f8\u7b49\u7684\u60c5\u51b5\u4e0b\uff0c\u5e73\u884c\u56db\u8fb9\u5f62\u9762\u79ef\u4e00\u5b9a\u5c0f\u4e8e\u6b63\u65b9\u5f62\u548c\u957f\u65b9\u5f62\uff1b\u7531\u6b64\u518d\u6bd4\u8f83\u5706\u3001\u6b63\u65b9\u5f62\u53ca\u957f\u65b9\u5f62\u5728\u5468\u957f\u76f8\u7b49\u7684\u60c5\u51b5\u4e0b\uff0c\u54ea\u79cd\u56fe\u5f62\u9762\u79ef\u6700\u5927\uff1b\u8bbe\u4e00\u4e2a\u5706\u7684\u534a\u5f84\u662f1\uff0c\u5b83\u7684\u5468\u957f\u662f6.28\uff0c\u9762\u79ef\u662f3.14\uff0c\u548c\u5b83\u5468\u957f\u76f8\u7b49\u7684\u6b63\u65b9\u5f62\u7684\u9762\u79ef\u662f\uff1a\uff086.28\u00f74\uff09 2 =2.4649\uff0c\u548c\u5b83\u5468\u957f\u76f8\u7b49\u7684\u957f\u65b9\u5f62\u7684\u9762\u79ef\u662f\uff1a6.28\u00f72=3.14\uff0c\u8bbe\u8fd9\u4e2a\u957f\u65b9\u5f62\u7684\u957f\u3001\u5bbd\u5206\u522b\u4e3aa\u3001b\uff1a\u53d6\u4e00\u4e9b\u6570\u5b57\uff080.1\uff0c3.04\uff09\uff0c\uff080.5\uff0c2.64\uff09\uff0c\uff081\uff0c2.14\uff09\uff0c\u2026\uff082.14\uff0c1\uff09\uff0c\uff082.64\uff0c0.5\uff09\uff0c\uff083.04\uff0c0.1\uff09\u53ef\u4ee5\u53d1\u73b0\u957f\u65b9\u5f62\u7684\u957f\u548c\u5bbd\u8d8a\u63a5\u8fd1\uff0c\u9762\u79ef\u5c31\u8d8a\u5927\uff0c\u5f53\u957f\u548c\u5bbd\u76f8\u7b49\u65f6\uff0c\u4e5f\u5c31\u662f\u53d8\u6210\u6b63\u65b9\u5f62\u4e86\uff0c\u6240\u4ee5\u8fd9\u4e2a\u957f\u65b9\u5f62\u7684\u9762\u79ef\u4e00\u5b9a\u5c0f\u4e8e\u6b63\u65b9\u5f62\u7684\u9762\u79ef\uff0e\u6240\u4ee5\u5728\u5468\u957f\u76f8\u7b49\u7684\u60c5\u51b5\u4e0b\uff0c\u9762\u79ef\uff1a\u5706\uff1e\u6b63\u65b9\u5f62\uff1e\u957f\u65b9\u5f62\uff1e\u5e73\u884c\u56db\u8fb9\u5f62\uff0e\u6545\u9009\uff1aD\uff0e
应该是圆形面积最大，其它的都不是最大周长相等时，正方形面积最大
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