一个圆锥的底面半径为4cm,母线长是5cm,求这个圆锥的体积(要过程) 如图,圆锥的母线长为4cm,底面直径为2cm.(1)求圆锥的...
\u5e95\u9762\u534a\u5f84\u4e3a5cm\uff0c\u6bcd\u7ebf\u957f\u4e3a4cm\u7684\u5706\u67f1\u4f53\u79ef\u4e3a\uff1f\u5140x25\u00d74=100\u5140
\uff081\uff09\u8bbe\u5706\u9525\u7684\u9ad8\u4e3ah\uff0c\u5e95\u9762\u534a\u5f84\u4e3ar\uff0cr=1\uff0c\u6bcd\u7ebfSA=4\uff0e\u2234h\uff1dSA2?r2\uff1d42?12\uff1d15\u5706\u9525\u7684\u4f53\u79ef\u4e3a\uff1aV=13\u00d7\u03c0\u00d715=153\u03c0\uff0e\uff082\uff09\u8bbe\u5706\u9525\u7684\u4fa7\u9762\u5c55\u5f00\u56fe\u4e3aSAA'\uff0c\u5219\u7531\u70b9A\u7ed5\u5706\u9525\u4e00\u5468\u56de\u5230\u70b9B\u7684\u6700\u77ed\u8ddd\u79bb\u4e3aBA'\u2235\u2220ASA\u2032\uff1d2\u03c0rSA\uff1d2\u03c0\u00d714\uff1d\u03c02\uff0cSB=3\uff0cSA'=4\u2234BA'=5\uff08cm\uff09\u7531\u70b9A\u7ed5\u5706\u9525\u4e00\u5468\u56de\u5230\u70b9B\u7684\u6700\u77ed\u8ddd\u79bb5cm\uff0e
圆锥的高:√(25-16)=3厘米圆锥的体积:(1/3)*3.14*4*4*3=50.24立方厘米
绛旓細鍥犱负 鎵浠=1/3*3.14*16*9 =151.68锛堢珛鏂鍘樼背锛1绔嬫柟鍘樼背=1姣崌 鎵浠ユ湁151.68姣崌婧㈠嚭
绛旓細浣犲ソ锛鍦嗛敟搴闈㈢Н=3.14脳4²=50.24锛堝钩鏂鍘樼背锛夊渾鏌变綋绉=1/3脳50.24脳6=100.48锛堢珛鏂瑰帢绫筹級鍦嗘煴搴曢潰绉=3.14脳3²=28.26锛堝钩鏂瑰帢绫筹級姘存繁=100.48梅28.26鈮3.6锛堝帢绫筹級
绛旓細姝ゅ渾鍙颁负涓涓埅椤鍦嗛敟 鍦嗛敟楂=2x4=8 鍦嗗彴鐨勪晶闈㈢Н=4蟺 鈭氾紙4²+8²锛-3蟺 鈭氾紙3²+4²锛夆増112,4-47,1 鈮65,3锛cm²锛
绛旓細=80 L1=4鈭5cm锛L2²=(H+4)²+6²=12²+6²=180锛孡2=6鈭5cm;鍦嗗彴鐨勫叏闈㈢Н=澶鍦嗛敟鐨渚ч潰绉-灏忓渾閿ョ殑渚ч潰绉+涓婂簳闈㈢Н+涓嬪簳闈㈢Н =L2*2*蟺*6/2-L1*2*蟺*4/2+蟺*6²+蟺*4²=6鈭5*6蟺-4鈭5*4蟺+52蟺 =(52+20鈭5)蟺(cm²)...
绛旓細璺熷彿3闄や互3锛岀劧鍚庡啀涔樹互鍦嗗懆鐜3.14 璁鍦嗛敟鐨勫簳闈㈠崐寰勪负r,鐢卞凡鐭ワ紝姣嶇嚎闀縇=4 鍙堝渾閿ョ殑渚ч潰灞曞紑鍥炬槸涓涓崐寰勪负4cm鐨勫崐鍦 鈭 2蟺r=蟺L 鈭 L=2r=4 鈭 r=2 鈭 h=鈭(L²-r²)=2鈭3 鈭 鍦嗛敟鐨勪綋绉疺=(1/3)蟺r²*h=(1/3)*蟺*4*2鈭3=8鈭3蟺/3 璁惧渾閿ョ殑搴曢潰...
绛旓細=蟺*2*4+蟺*2*2 =12蟺 涓嶇煡閬撲綘鐨勯蟺鐨勫彇鍊 缁撴灉浣犺嚜宸辩畻灏辫浜
绛旓細灏辨槸涓涓崐寰勪负4cm锛寮ч暱涓2*3*3.14cm鍥存垚鎵囧舰鐨勯潰绉
绛旓細鍦嗛敟鐨勫簳闈鍛ㄩ暱灏辨槸鎵囧舰鐨勫姬闀跨瓑浜2蟺脳4脳120/360=8蟺/3鎵浠搴曢潰鍗婂緞=8蟺/3梅(2蟺)=4/3鍦嗛敟姣绾块暱绛変簬鎵囧舰鍗婂緞鎵浠ラ珮=鏍瑰彿[4骞虫柟-(4/3)骞虫柟]=3鍒嗕箣8鍊嶆牴鍙2
绛旓細鍒嗘瀽锛氬渾閿ョ殑渚ч潰绉=搴曢潰鍛ㄩ暱×姣嶇嚎闀÷2锛屾妸鐩稿簲鏁板间唬鍏ュ嵆鍙眰瑙o紟瑙g瓟锛氳В锛氬渾閿ョ殑渚ч潰绉=2蟺×4×2÷2=8蟺锛庢晠绛旀涓猴細8蟺锛庣偣璇勶細鏈鑰冩煡浜嗗渾閿ョ殑璁$畻锛岃В棰樼殑鍏抽敭鏄紕娓呭渾閿ョ殑渚ч潰绉殑璁$畻鏂规硶锛岀壒鍒鏄渾閿ョ殑搴曢潰鍛ㄩ暱绛変簬鍦嗛敟鐨勪晶闈鎵囧舰鐨勫姬闀匡紟
绛旓細鍦嗛敟鐨渚ч潰绉=2蟺脳4脳2梅2=8蟺锛庢晠绛旀涓猴細8蟺锛