做一个无盖的圆形铁皮水桶，底面半径是25厘米，高是50厘米，做一只这样的水桶约需多少平方厘米铁皮？ 一个无盖的圆柱形铁皮水桶，底面直径是20厘米，高是25厘米．...
\u4e00\u4e2a\u65e0\u76d6\u5706\u67f1\u4f53\u94c1\u76ae\u6c34\u6876\u5e95\u9762\u534a\u5f84\u662f25\u5398\u7c73\uff0c\u9ad8\u662f50\u5398\u7c73\u8fd9\u6837\u505a\u4e00\u53ea\u6c34\u6876\u5927\u7ea6\u9700\u8981\u591a\u5c11\u5e73\u65b9\u5398\u7c73\u7684\u94c1\u76ae\u91c7\u7eb3\u54df😊
\u6c34\u6876\u7684\u4fa7\u9762\u79ef\uff1a3.14\u00d720\u00d725=1570\uff08\u5e73\u65b9\u5398\u7c73\uff09\uff0c\u6c34\u6876\u7684\u5e95\u9762\u79ef\uff1a3.14\u00d7\uff0820\u00f72\uff092=3.14\u00d7102=314\uff08\u5e73\u65b9\u5398\u7c73\uff09\uff0c\u6c34\u6876\u7684\u8868\u9762\u79ef\uff1a1570+314=1884\uff08\u5e73\u65b9\u5398\u7c73\uff09\uff1b\u7b54\uff1a\u505a\u4e00\u4e2a\u8fd9\u6837\u7684\u6c34\u6876\u5927\u7ea6\u7528\u94c1\u76ae1884\u5e73\u65b9\u5398\u7c73\uff0e
25的平方X3.14=1962.5(平方厘米)25X2X3.14X50=7850(平方厘米)
1962.5+7850=9812.5(平方厘米)
绛旓細25鐨勫钩鏂筙3.14=1962.5(骞虫柟鍘樼背)25X2X3.14X50=7850(骞虫柟鍘樼背)1962.5+7850=9812.5(骞虫柟鍘樼背)
绛旓細鏍规嵁棰樼洰涓粰鍑虹殑鍙傛暟锛岃鍋氫竴涓棤鐩栫殑鍦嗘煴褰㈤搧鐨按妗锛搴曢潰鐩村緞涓哄洓鍘樼背锛岄珮涓轰簲鍘樼背锛岃嚦灏戦渶瑕佸灏戝钩鏂瑰垎绫崇殑閾佺毊銆傛牴鎹渾鏌变綋鍏紡璁＄畻锛岃繖涓按妗舵墍闇瑕佺殑鏈灏忚〃闈㈢Н=2蟺rh+2蟺r^2=2蟺*4*5+2蟺*16=120.96骞虫柟鍘樼背銆傚洜姝わ紝鑷冲皯瑕佺敤120.96骞虫柟鍒嗙背鐨勯搧鐨潵鍋氳繖涓渾鏌卞舰姘存《銆
绛旓細绛旓細鍋氳繖涓姘存《鑷冲皯闇瑕閾佺毊75.36骞虫柟鍒嗙背銆
绛旓細搴曢潰鍛ㄩ暱=20蟺鍘樼背锛屼晶闈㈢Н=20蟺脳3=60蟺骞虫柟鍘樼背锛屽簳闈㈢Н=蟺r²=蟺10²=100蟺骞虫柟鍘樼背 鎵浠ユ婚潰绉负160蟺骞虫柟鍘樼背鈮502.65骞虫柟鍘樼背
绛旓細4*3.14*5+2*2*3.14=75.36骞虫柟鍒嗙背
绛旓細S渚 + S搴 = 蟺dh + 蟺r^2 = 蟺锛20脳40 + 100锛=900蟺 = 2826骞虫柟鍘樼背绛旓細鑷冲皯闇瑕2826骞虫柟鍘樼背
绛旓細3.14*20骞虫柟=1256锛堝钩鏂瑰帢绫筹級4鍒嗙背=40鍘樼背 2*3.14*20*4=502.4锛堝钩鏂瑰帢绫筹級1256+502.4=1758.4锛堝钩鏂瑰帢绫筹級绛旓細鍋氳繖涓姘存《鑷冲皯闇瑕1758.4骞虫柟鍘樼背閾佺毊銆
绛旓細浣犲ソ锛40鍘樼背=4鍒嗙背 搴曢潰绉=3.14脳锛4梅2锛²=12.56锛堝钩鏂瑰垎绫筹級渚ч潰绉=3.14脳4脳5=62.8锛堝钩鏂瑰垎绫筹級闇瑕閾佺毊闈㈢Н=62.8+12.56=75.36锛堝钩鏂瑰垎绫筹級
绛旓細搴曢潰鍗婂緞锛4梅2=2锛堝垎绫筹級搴曢潰绉細2脳2脳3.14=12.56锛堝钩鏂瑰垎绫筹級渚ч潰绉細4脳3.14脳4=50.24锛堝钩鏂瑰垎绫筹級闇瑕閾佺毊锛12.56+50.24=62.8锛堝钩鏂瑰垎绫筹級姘存《鐨勫绉槸锛12.56脳4=50.24锛堢珛鏂瑰垎绫筹級=50.24锛堝崌锛
绛旓細3.1416脳30²+2脳3.1416脳50梅100=2830.5816骞虫柟绫 3.1416脳30²脳50梅100=1413.72绔嬫柟绫 绛旓細濡傛灉涓嶈冭檻鎺ョ紳鐨勫洜绱犲仛姝ゆ按妗堕渶2830.5816骞虫柟绫閾佺毊锛屾渶澶氳兘瑁1413锛.72绔嬫柟绫虫按銆傦紙杩欎篃涓嶆槸姘存《锛鍒嗘槑鏄釜闈炲父澶х殑閾佺洏锛
