底面内直径2米,深3米的圆柱蓄水池。要把这个水池的内壁及底面抹上水泥,抹水泥部分的面积是多少?
\u4e00\u4e2a\u5706\u67f1\u5f62\u7684\u84c4\u6c34\u6c60\uff0c\u5e95\u9762\u5185\u76f4\u5f84\u662f2\u7c73\uff0c\u6df12\u7c73\uff0c\u5728\u6c60\u7684\u5185\u58c1\u4e0e\u5e95\u9762\u62b9\u6c34\u6ce5\uff0c\u62b9\u6c34\u6ce5\u90e8\u5206\u7684\u9762\u79ef\u662f\u591a\u5c11\u5e73\u65b9\u7c73\uff1f\u4f60\u4e0d\u4f1a\uff1f\uff1f\uff1f
2\u00d73.14\u00d72+3.14\u00d7\uff082\u00f72\uff09\u7684\u5e73\u65b9
=12.56+3.14
=15.7\u5e73\u65b9\u7c73
\u7ed9\u5206\u5427
\u5e95\u9762\u534a\u5f84\u662f
6\u00f72\uff1d3\uff08\u7c73\uff09
\u5e95\u9762\u79ef\u662f
3\u00d73\u00d73.14\uff1d28.26\uff08\u5e73\u65b9\u7c73\uff09
\u4fa7\u9762\u79ef\u662f
6\u00d73.14\u00d72.5\uff1d47.1\uff08\u5e73\u65b9\u7c73\uff09
\u9700\u8981\u62b9\u6c34\u6ce5\u7684\u90e8\u5206\u7684\u9762\u79ef\u662f
28.26\uff0b47.1\uff1d75.36\uff08\u5e73\u65b9\u7c73\uff09
\u7ed9\u6c34\u6c60\u91cc\u704c2\u7c73\u6df1\u7684\u6c34\u8fd9\u4e9b\u6c34\u7684\u4f53\u79ef\u662f
28.26\u00d72\uff1d56.52\uff08\u7acb\u65b9\u7c73\uff09
1、
底面积=3.14×(2÷2)²=3.14(平方米)
侧面积=3.14×2×3=18.84(平方米)
抹水泥面积=18.84+3.14=21.98(平方米)
2、
3米=30分米
3.14×2×2×30×2
=12.56×30×2
=753.6(平方分米)
绛旓細浣犲ソ锛1銆搴曢潰绉=3.14脳锛2梅2锛²=3.14锛堝钩鏂圭背锛変晶闈㈢Н=3.14脳2脳3=18.84锛堝钩鏂圭背锛夋姽姘存偿闈㈢Н=18.84+3.14=21.98锛堝钩鏂圭背锛2銆3绫=30鍒嗙背 3.14脳2脳2脳30脳2 =12.56脳30脳2 =753.6锛堝钩鏂瑰垎绫筹級
绛旓細锛1锛3.14脳2脳3+3.14脳锛2梅2锛2=18.84+3.14=21.98锛堝钩鏂圭背锛夌瓟锛氭姽姘存偿閮ㄥ垎鐨勯潰绉槸21.98骞虫柟绫筹紟锛2锛3.14脳(22)2脳3=3.14脳3=9.42锛堢珛鏂圭背锛夛紱绛旓細钃姘存睜鐨勫绉槸9.42绔嬫柟绫筹紟
绛旓細3.14脳2 脳3+3.14 脳锛2梅2锛夌殑骞虫柟=21.98骞虫柟绫 QAQ 鎴戝彂鐜扮殑鎱簡鈥︹
绛旓細姘翠綋绉細蟺(d/2)²h=3.14x锛2/2锛²x3=9.42绔嬫柟绫炽傛湜閲囩撼锛岃阿璋
绛旓細锛1锛3.14脳3脳2+3.14脳锛3梅2锛2=18.84+7.065=25.905锛堝钩鏂圭背锛夛紝锛2锛3.14脳锛3梅2锛2脳2=3.14脳2.25脳2=14.13锛堢珛鏂圭背锛夛紟绛旓細鎶规按娉ラ儴鍒嗙殑闈㈢Н鏄25.905骞虫柟绫筹紝杩欎釜姘存睜鑳借搫姘14.13绔嬫柟绫筹紟
绛旓細kahnmao 涓炬姤 涓涓渾閿ュ舰灏忛害鍫 娴嬪緱搴曢潰鍛ㄩ暱12路56绫 楂0路6绫 灏嗚繖鍫嗗皬楹﹁鍏搴曢潰鐩村緞鏄4绫崇殑鍦嗘煴褰㈢伯浠鍐咃紝灏忛害鐨勯珮 搴曢潰鍗婂緞鏄細12.56梅3.14梅2=2绫 搴曢潰绉槸锛3.14脳2²=12.56骞虫柟绫 浣撶Н鏄細12.56脳0.6梅3=2.512绔嬫柟绫 绮粨搴曢潰绉槸锛3.14脳锛4梅2锛²=12....
绛旓細蟺脳2²脳3梅锛1/3脳蟺脳1²脳1.2锛夛紳30
绛旓細瑙o細鐢遍鎰忓彲鐭ワ紝鍒 搴曢潰鍦嗛潰绉=蟺R²=蟺x锛3梅2锛²=7.065锛堝钩鏂圭背锛夋按姹犲绉=搴曢潰绉痻楂=蟺R²H=7.065x3=21.195锛堢珛鏂圭背锛夌瓟锛氭按姹犲绉负21.195绔嬫柟绫炽傜瓟棰樹笉鏄擄紝鏈涢噰绾硚~~
绛旓細闈㈢Н2/2=1 1*1*3.14=3.14 3.14+2*3.14*1=9.42骞虫柟绫 钃勬按 1*1*3.14*2=6.28绔嬫柟绫
绛旓細鍦嗘煴鐨勫懆闀夸负锛2X3.14=6.28绫 渚ч潰绉负锛6.28X2=12.56绫²搴曢潰绉负锛3.14X1²=3.14绫²鎶规按娉ラ潰绉负锛氬簳闈㈢Н+渚ч潰绉=12.56+3.14=15.7绫²钃勬按浣撶Н涓猴細搴曢潰绉疿楂=3.14X2=6.28绫³