一个圆锥的高和底面半径都等于一个正方体的棱长，已知这个正方体的体积是90立方厘米，这个圆锥的体积是？
\u5706\u9525\u7684\u9ad8\u548c\u5e95\u9762\u534a\u5f84\u90fd\u7b49\u4e8e\u4e00\u4e2a\u6b63\u65b9\u4f53\u7684\u68f1\u957f\u3002\u5df2\u77e5\u6b63\u65b9\u4f53\u7684\u4f53\u79ef\u662f90\u7acb\u65b9\u5398\u7c73\uff0c\u4f60\u77e5\u9053\u5706\u9525\u7684\u4f53\u79ef\u662f\u591a\u5c11\u5417\uff1f\u56e0\u4e3a\u5706\u9525\u7684\u9ad8\u548c\u5e95\u9762\u534a\u5f84\u90fd\u7b49\u4e8e\u4e00\u4e2a\u6b63\u65b9\u4f53\u7684\u68f1\u957f\uff0c\u6240\u4ee5\u9ad8\u7b49\u4e8e\u534a\u5f84
\u5706\u9525\u7684\u4f53\u79ef=1/3\u00d7\u5e95\u9762\u9762\u79ef\u00d7\u9ad8\u03c0 = 1/3 \u00d7\u534a\u5f84\u7684\u5e73\u65b9\u00d7\u03c0\u00d7\u9ad8=1/3\u00d7\u68f1\u957f\u7684\u5e73\u65b9\u00d7 \u03c0\u00d7\u68f1\u957f = 1/3\u00d7 \u68f1\u957f \u7684\u7acb\u65b9\u00d7\u03c0 = 1/3 \u00d7 90 \u00d7 \u03c0 = 30\u03c0 \uff08 \u4e00\u822c \u03c0 \u53d6\u503c3.14 \uff09
\u8bbe\u6b63\u65b9\u4f53\u7684\u68f1\u957f\u4e3aa\uff0c\u6b63\u65b9\u4f53\u7684\u4f53\u79ef\u662f30\u7acb\u65b9\u5398\u7c73\uff0c\u5219\uff1a
a\u00d7a\u00d7a\uff1d30\uff08\u7acb\u65b9\u5398\u7c73\uff09
\u5706\u9525\u7684\u4f53\u79ef\u4e3a\uff1a3.14\u00d7r^2\u00d7h\u00d71/3
\u56e0\u4e3a\uff1a\u9ad8\u548c\u5e95\u9762\u534a\u5f84\u90fd\u7b49\u4e8e\u6b63\u65b9\u4f53\u7684\u68f1\u957fa\uff0c\u6240\u4ee5\u5706\u9525\u7684\u4f53\u79ef\u4e3a\uff1a
3.14\u00d7r^2\u00d7h\u00d71/3
\uff1d3.14\u00d7a^2\u00d7a\u00d71/3
\uff1d3.14\u00d730\u00d71/3
\uff1d31.4\uff08\u7acb\u65b9\u5398\u7c73\uff09
圆锥体积为:1/3*3.14*R3,上式代入,则为1/3*3.14*90=94.2立米厘米.
你几年级的?小学一年级吧.
a^3=90cm^3
V圆锥=1/3*πa^2*a
90除3算出高和底面半径，在乘3。半径2乘3。14乘高乘1/3
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