六上年级数学计算阴影部分面积和周长
\u516d\u5e74\u7ea7\u4e0a\u518c\u6570\u5b66\u9634\u5f71\u90e8\u5206\u7684\u5468\u957f\u548c\u9762\u79ef\u60a8\u597d\uff0c\u5bd2\u6a31\u6696\u6696\u4e3a\u4f60\u89e3\u7b54\uff1a
\u7b2c\u4e8c\u5f20\u7684\uff1a
2\u00d71/4\u00d73.14\u00d73\u00d73-3\u00d73
=14.13-9
=5.13\u5e73\u65b9\u5398\u7c73
\u5982\u679c\u4f60\u8ba4\u53ef\u6211\u7684\u56de\u7b54\uff0c
\u8bf7\u53ca\u65f6\u70b9\u51fb\u3010\u91c7\u7eb3\u4e3a\u6ee1\u610f\u56de\u7b54\u3011\u6309\u94ae\uff0c\uff08\u6216\u5728\u5ba2\u6237\u7aef\u53f3\u4e0a\u89d2\u8bc4\u4ef7\u70b9\u3010\u6ee1\u610f\u3011\uff09
\u4f60\u7684\u91c7\u7eb3\uff0c
\u662f\u6211\u524d\u8fdb\u7684\u52a8\u529b! \u4e5f\u4f1a\u7ed9\u4f60\u5e26\u53bb\u8d22\u5bcc\u503c\u7684\u3002
\u5982\u6709\u4e0d\u660e\u767d\uff0c
\u53ef\u4ee5\u8ffd\u95ee\uff0c\u76f4\u5230\u5b8c\u6210\u5f04\u61c2\u6b64\u9898!
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\u91c7\u7eb3\u4e86\uff0c\u6211\u53ef\u4ee5\u3010\u518d\u5e2e\u4f60\u505a\u7b2c\u4e00\u5f20\u7684\u90a3\u9898\u3011\uff01\uff01\uff01
\u91c7\u7eb3\u540e\uff0c\u8fd8\u8981\u8ffd\u95ee\u54df\uff0c\uff08\u53ef\u4ee5\u53ea\u53d1\u4e00\u4e2a\u95ee\u53f7\u3002\uff09\u4e0d\u7136\u5e2e\u4e0d\u5230\u4f60\u3002
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\u7b2c\u4e00\u9898\uff1a\u5468\u957f\u4e3a6\u00d73.14\uff0b6\uff0b6\uff1d30.84 \u9762\u79ef\u4e3a36-9\u00d73.14\uff1d7.74 \u7b2c\u4e8c\u9898\uff1a\u5468\u957f\u4e3a3.14\u00d74\u00f72+2+2+4\uff1d14.28 \u9762\u79ef\u4e3a2\u00d74-4\u00f72\u00d73.14\uff1d1.72
解：左右两个半圆合起来刚好是一个圆
阴影部分面积
=4×4-π×(4÷2)²
=16-4π
阴影部分周长
=π×4+4+4
=4π+8
面积：10*10-25π
=100-25π
周长：10π+2*10
=10π+20
π按照题目中所要的取值
C=10+10+10×3.14=51.4cm
S=10×10-(10÷2)²×3.14=21.5cm²
绛旓細鍏1銆闈㈢Н3.14脳锛4/2锛²脳1/2+4脳6=6.28+24=30.28骞虫柟鍒嗙背 鍛ㄩ暱6脳2+4+3.14脳4脳1/2=12+4+6.28=22.28鍒嗙背 2銆侀潰绉8²-3.14脳锛8/2锛²=64-50.24=13.76骞虫柟鍒嗙背 鍛ㄩ暱3.14脳8=25.12鍒嗙背 3銆侀潰绉3.14脳銆愶紙10/2锛²-锛6/2锛²銆=3...
绛旓細闃村奖閮ㄥ垎闈㈢Н =4脳4-蟺脳(4梅2)²=16-4蟺 闃村奖閮ㄥ垎鍛ㄩ暱 =蟺脳4+4+4 =4蟺+8
绛旓細绗竴姝ワ紝鍏绠s1鍜宻2鐨闈㈢Н涔嬪拰锛氱浜屾锛岀敱鍦嗗懆瑙掍笌鍦嗗績瑙掔殑鎬ц川鏈塨 = 2a锛屽悓鏃跺凡鐭ワ細锛屽彲寰 锛屽嵆寰 锛岀涓夋锛屽尯鍩3宸︾鐐瑰埌涓績姘村钩绾跨殑璺濈涓4 鎵浠ワ紝鍖哄煙3鐨勯潰绉负锛氱鍥涙锛岀患涓婃墍杩帮紝闃村奖閮ㄥ垎鐨勯潰绉负锛
绛旓細L=3.14x10+10+10+20=71.4 S=10x20-3.14x10x10梅2=43 2銆丩=3.14x10梅2+3.14x4梅2+锛10-4锛=27.98鍘樼背 S=3.14x5x5梅2-3.14x2x2梅2=32.97骞虫柟鍘樼背 鏈嬪弸锛岃銆愰噰绾崇瓟妗堛戯紝鎮ㄧ殑閲囩撼鏄垜绛旈鐨勫姩鍔涳紝璋㈣阿銆
绛旓細涓婂浘锛氬懆闀匡紳1/4鍗婂緞涓4鐨勫渾鍛ㄩ暱+鍗婂緞+1/2鐩村緞4鐨勫渾鐨勫懆闀 锛1/4脳4脳2脳蟺+4+1/2脳4脳蟺 锛2蟺+4+2蟺 锛4蟺+4 闈㈢Н锛1/4鍗婂緞涓4鐨勫渾闈㈢Н-1/2鍗婂緞涓2鐨勫渾闈㈢Н 锛1/4脳4²蟺-1/2锛4/2锛²蟺 锛4蟺-2蟺 锛2蟺 涓嬪浘 鍛ㄩ暱锛3/4鍗婂緞涓6鐨勫渾鍛ㄩ暱+1/4鍗婂緞涓...
绛旓細浣滆緟鍔╃嚎锛岀┖鐧戒袱鍧=绾㈢嚎涓婄殑涓ゅ皬鍧楋紱寰 闃村奖闈㈢Н=涓夎褰㈤潰绉=8脳8梅2=32锛涢槾褰卞懆闀=涓ゆ潯鍦嗗姬+涓や釜鐩村緞 =8脳3.14+8脳2 =25.12+16 =41.12
绛旓細瑙ｏ細1銆侀槾褰遍儴鍒嗗懆闀=2*1/4*3.14*4+1/2*3.14*4=6.28+6.28=12.56cm;2銆闃村奖閮ㄥ垎闈㈢Н=姊舰闈㈢Н-鍗婂渾闈㈢Н=1/2*4锛10+8锛-1/2*3.14*4²=10.88cm²
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绛旓細闃村奖閮ㄥ垎鐨闈㈢Н鍙互閫氳繃璁＄畻缁勫悎鍥惧舰鐨勯潰绉潵姹寰椼傚叿浣撴楠ゅ涓嬶細1. 鍒嗗埆璁＄畻闀挎柟褰㈠拰鍦嗙殑闈㈢Н銆傚凡鐭ラ暱鏂瑰舰鐨勯暱涓8鍘樼背锛屽涓4鍘樼背锛屾墍浠ラ暱鏂瑰舰鐨勯潰绉负锛歋₁=闀×瀹=8鍘樼背×4鍘樼背=32骞虫柟鍘樼背銆傚凡鐭ュ渾鐨勫崐寰勪负3鍘樼背锛屾牴鎹渾鐨勯潰绉叕寮廠₂=π×r²锛屽彲璁＄畻鍑...
绛旓細68锛堝钩鏂瑰帢绫筹級浣滀笟鏈焊 锛1锛闃村奖闈㈢Н=澶у渾闈㈢Н-灏忓渾闈㈢Н=3.14*8*8-3.14*6*6=87.92 2锛9*9-3.14*4.5*4.5=81-63.585=17.415 锛堬級1/4*3.14*9*9=63.585 8.闀挎柟褰㈤潰绉=闀縳瀹=16x瀹 鍦 闈㈢Н=蟺x锛16/2锛²=64蟺 鎵浠ュ=64蟺/16=4蟺=12.56锛堝帢绫筹級...
