一个圆锥形小麦，底面周长31.4米，高3米，底面直径4分米，做这样一个水桶至少需要多少铁皮？
\u4e00\u4e2a\u5706\u9525\u5f62\u5c0f\u9ea6\u5806\uff0c\u5730\u9762\u5468\u957f\u662f15.7\u7c73\uff0c\u9ad8\u662f3\u7c73\uff0c\u628a\u8fd9\u5806\u5c0f\u9ea6\u88c5\u8fdb\u5730\u9762\u76f4\u5f84\u662f4\u7c73\u7684\u5706\u3010\u5206\u6790\u3011
\u6b64\u9898\u662f\u6c42\u5c06\u5706\u9525\u5f62\u9ea6\u5b50\u88c5\u5165\u5706\u67f1\u5f62\u7cae\u56e4\u540e\uff0c\u9ea6\u5b50\u7684\u9ad8\u5ea6\u3002
\u88c5\u5165\u7cae\u56e4\u524d\u540e\u9ea6\u5b50\u4f53\u79ef\u4e0d\u53d8\u3002
\u5148\u7b97\u51fa\u9525\u5f62\u9ea6\u5806\u4f53\u79ef\uff0c\u7136\u540e\u7528\u6b64\u4f53\u79ef\u9664\u4ee5\u5706\u67f1\u5f62\u7cae\u56e4\u5e95\u9762\u79ef\uff0c\u5c31\u5f97\u9ea6\u5b50\u5728\u7cae\u56e4\u4e2d\u7684\u9ad8\u5ea6\u3002
\u3010\u89e3\u3011
\u9ea6\u5806\u5e95\u9762\u534a\u5f84=15.7\u00f73.14\u00f72
=2.5\uff08\u7c73\uff09
\u9ea6\u5806\u5e95\u9762\u79ef=2.5\u00d72.5\u00d73.14
=19.625\uff08\u5e73\u65b9\u7c73\uff09
\u9ea6\u5806\u4f53\u79ef=19.625\u00d73\u00f73
=19.625\uff08\u7acb\u65b9\u7c73\uff09
\u5706\u67f1\u5f62\u7cae\u56e4\u5e95\u9762\u79ef=\uff084\u00f72\uff09\u00d7\uff084\u00f72\uff09\u00d73.14
=12.56\uff08\u5e73\u65b9\u7c73\uff09
\u56e4\u5185\u5c0f\u9ea6\u9ad8=19.625\u00f712.65
=1.5625\uff08\u7c73\uff09
\u7b54\uff1a\u628a\u8fd9\u5806\u5c0f\u9ea6\u88c5\u8fdb\u5730\u9762\u76f4\u5f84\u662f4\u7c73\u7684\u5706\u67f1\u5f62\u7cae\u56e4\u540e\uff0c\u9ad8\u5ea6\u4e3a1.5625\u7c73\u3002
\u5706\u9525\u534a\u5f84=18.84\u00f72\u00f73.14=3\u7c73
\u9ad8=2\u7c73
\u5706\u67f1\u534a\u5f84=2\u7c73
\u53ef\u4ee5\u88c5\u7684\u9ad8\u5ea6
=\u5706\u9525\u4f53\u79ef\u00f7\u5706\u67f1\u5e95\u9762\u79ef
=\uff083\u5206\u4e4b1\u00d73.14\u00d73²\u00d72\uff09\u00f7\uff083.14\u00d72²\uff09
=1.5\u7c73
\u5f88\u9ad8\u5174\u4e3a\u4f60\u89e3\u7b54\uff0c\u795d\u4f60\u5b66\u4e60\u8fdb\u6b65\uff01\u4e00\u523b\u6c38\u8fdc523 \u4e3a\u4f60\u89e3\u7b54~~
\u5982\u679c\u4f60\u8ba4\u53ef\u6211\u7684\u56de\u7b54\uff0c\u8bf7\u70b9\u51fb\u4e0b\u9762\u7684\u3010\u9009\u4e3a\u6ee1\u610f\u56de\u7b54\u3011\u6309\u94ae\uff0c\u8c22\u8c22~~
\u5982\u679c\u8fd8\u6709\u5176\u5b83\u95ee\u9898\uff0c\u8bf7\u53e6\u5916\u5411\u6211\u6c42\u52a9\uff0c\u7b54\u9898\u4e0d\u6613\uff0c\u656c\u8bf7\u7406\u89e3~~
=3.14×(4÷2)²+3.14×4×3=50.24 DM²
绛旓細鍗婂緞=鍛ㄩ暱梅6.28=31.4梅6.28=5鍒嗙背 鍦嗛敟鐨浣撶Н=1/3脳搴曢潰绉楅珮 =3.14脳5 ²脳1.8脳1/3 =78.5脳1.8脳1/3 =141.3梅3=47.1绔嬫柟鍒嗙背 2.5绫=25鍒嗙背 鍦嗘煴鐨勫簳闈㈢Н=浣撶Н梅楂 =47.1梅25 =1.884骞虫柟鍒嗙背 绛旓細瀹冪殑搴曢潰绉槸1.884骞虫柟鍒嗙背 ...
绛旓細瑙ｆ瀽锛氭牴鎹渾閿ョ殑浣撶Н鍏紡姹傚嚭楹﹀爢鐨勪綋绉細鍏堟牴鎹鍦嗛敟鐨勫簳闈㈠懆闀姹傚嚭瀹冪殑搴曢潰鍗婂緞鏄細31.4梅3.14梅2=5绫筹紝浠ｅ叆鍦嗛敟鐨勪綋绉叕寮忓嵆鍙绠楋紱鐒跺悗鐢ㄦ眰鍑鐨勫皬楹鐨勪綋绉紝闄や互绮洡鐨勯珮锛屽氨鏄伯鍥ょ殑搴曢潰绉傝В锛氾紙31.4梅3.14梅2锛²脳3.14脳1.5脳1/3 =25脳3.14脳1.5脳1/3 =117.75脳1/...
绛旓細31.4梅3.14梅2=5绫筹紙搴曞崐寰勶級5x5x3.14x1.8梅3=47.1绔嬫柟绫筹紙浣撶Н锛47.1梅2.5=18.84锛堢伯鍥ゅ簳闈㈢Н锛
绛旓細搴曢潰鍛ㄩ暱=2脳31.4脳r=31.4锛宺=5 鍦嗛敟褰㈠皬楹閲嶉噺=3.14脳5²脳1.5梅3脳800=31400鍏枻=31.4鍚
绛旓細31.4梅2蟺=5m,5²蟺*1.5*1/3=12.5蟺=39.25m³39.25梅10=3.925m²搴曢潰绉3.925m²
绛旓細涓涓渾閿ュ舰绮粨搴曢潰鍛ㄩ暱鏄31.4绫抽珮涓夌背姣忕珛鏂圭背灏忛害閲600鍗冨厠杩欎釜绮粨鏈澶氬彲锛熺洿寰:31.4/3.14=10绫 鍗婂緞:10/2=5绫 浣撶Н(瀹圭Н):1/3x3.14x5x5x3 =78.5绔嬫柟绫 姣忕珛鏂圭背閲600鍗冨厠:78.5x600 =47100鍗冨厠 鏈澶氬彲浠ヨ47100鍗冨厠鐨勭伯椋 ...
绛旓細鍗婂緞31.4梅3.14梅2=5绫 浣撶Н3.14脳5脳5脳2.4脳1/3=62.8绔嬫柟绫 鎵浠ュ绉槸62.8梅3/9=188.4绔嬫柟绫
绛旓細鍦嗛敟鍗婂緞=31.4梅2梅3.14=5绫 绮粨鐨瀹圭Н=1/3脳3.14脳5²脳2.4梅2/9=282.6绔嬫柟绫 鏈変笉鏄庣櫧鐨勫湴鏂瑰啀闂摕锛岀浣犲涔犺繘姝ワ紝鏇翠笂涓灞傛ゼ锛 (*^__^*)
绛旓細鎮ㄥソ锛搴曢潰鍗婂緞 31.4梅锛2x3.14锛=5绫 搴曢潰绉 1/3x5x5x3.14x1.8梅10=4.71骞虫柟绫 涓嶆槑鐧斤紝鍙互杩介棶 濡傛湁甯姪锛岃寰楅噰绾筹紝璋㈣阿 绁濆涔犺繘姝ワ紒
绛旓細搴曞崐寰=31.4梅3.14梅2=5绫 浣撶Н=5脳5脳3.14脳1.5脳1/3=39.25绔嬫柟绫 璐ㄩ噺=39.25脳800=31400鍗冨厠=31.4鍚
