用一根铁丝把直径为20cm的两根同样细粗的圆木木捆在一起【接头处不计】,最少要几米长铁丝
\u7528\u4e24\u6839\u540c\u6837\u7c97\u7684\u94a2\u7ba1\u6346\u5728\u4e00\u8d77\uff0c\u94a2\u7ba1\u7684\u5916\u76f4\u5f84\u662f20cm\uff0c\u5982\u679c\u63a5\u5934\u5904\u4e0d\u8ba1\uff0c\u8fd9\u6839\u94c1\u4e1d\u81f3\u5c11\u591a\u957f3.14\u00d720\uff1d62.8\uff08\u5398\u7c73\uff09(\u4e00\u4e2a\u5706\u7684\u5468\u957f\uff09
20\u00d72=40\uff08\u5398\u7c73\uff09\uff08\u4e24\u6761\u76f4\u5f84)
62.8+20=82.8\uff08\u5398\u7c73)
3.2
3.14×10+10×2 一个圆+两条边
=31.4+20
=51.4cm
=0.514m
画图得:两个半圆和两个直径3.14*20+40=102.8cm=1.028m
20π+20+20=40+20π
绛旓細=0.514m
绛旓細涓涓渾鐨勫懆闀垮姞涓涓鐩村緞锛屽嵆绛変簬锕0.2锕0.2鈭忥箽绫
绛旓細閾佷笣闀垮害锛3.14脳20脳2+20脳2脳2=125.6+80=205.6锛屽叏闀205.6鍘樼背銆
绛旓細3.14x20+20+20=102.8鍘樼背 鎶婂畠浠洿鍦ㄤ竴璧蜂笉璁℃帴澶村涓鍏辩敤鍘102.8cm鐨閾佷笣銆傝寰楅噰绾冲晩
绛旓細20脳3.14+20脳2+5 =62.8+40+5 =107.8锛堝帢绫筹級鎹嗕竴鍛ㄨ嚦灏戦渶瑕107.8鍘樼背閾佷笣銆
绛旓細棣栧厛闇瑕佸皢涓や釜鏈ㄥご鎹嗗湪涓璧凤紝鑰冭檻灏嗛搧涓缁曟垚涓涓鍦嗙幆锛岀劧鍚灏嗕袱涓湪澶存斁鍦ㄥ渾鐜唴锛屼娇寰楀渾鐜揣绱у湴濂楀湪涓や釜鏈ㄥご涓娿傚浜鐩村緞涓20鍘樼背鐨勬湪澶达紝瀹冪殑鍛ㄩ暱鏄 2蟺脳10=20蟺 鍘樼背銆傚浜庣洿寰勪负10鍘樼背鐨勬湪澶达紝瀹冪殑鍛ㄩ暱鏄 2蟺脳5=10蟺 鍘樼背銆傚洜姝わ紝灏嗕袱涓湪澶存崋鍦ㄤ竴璧锋墍闇瑕佺殑閾佷笣闀垮害鏄 20蟺+10蟺=30...
绛旓細鑷冲皯=20脳3.14+20脳2=102.8鍘樼背 涓嶆噦鍙拷闂,鏈夊府鍔╄閲囩撼,璋㈣阿!
绛旓細鐢閾佷笣鎶2鏍妯埅闈鐩村緞閮鏄20鍘樼背鐨勫渾鏈ㄦ崋鍦ㄤ竴璧凤紝濡傛灉鎺ュご澶勯搧涓濋暱5鍘樼背锛岄偅涔堟崋涓鍛ㄨ嚦灏戦渶瑕107.8鍘樼背銆傝В绛旇繃绋嬪涓嬶細20脳2+3.14脳20+5 =40+62.8+5 =107.8锛堝帢绫筹級绛旓細鑷冲皯闇瑕107.8鍘樼背鐨勯搧涓濄
绛旓細714
绛旓細锛20x2+3.14x20锛墄2 =锛40+62.8锛墄2 =102.8x2 =205.6鍘樼背