把两根同样粗细的钢管用铁丝捆一圈，已知钢管外直径是3.5分米，至少要用铁丝多少分米、接头忽略不计
\u628a\u4e24\u6839\u540c\u6837\u7c97\u7ec6\u7684\u94a2\u7ba1\u6346\u4e00\u5708\uff0c\u5df2\u77e5\u94a2\u7ba1\u5916\u76f4\u5f84\u662f3.5\u5206\u7c73\uff0c\u81f3\u5c11\u8981\u7528\u94c1\u4e1d\u591a\u5c11\u5206\u7c73\uff1f\u63a5\u5934\u5ffd\u7565\u4e0d\u8ba1\u9700\u8981\uff1a4x3.5+3.14x3.5=24.99\u5206\u7c73
\u9700\u8981=3\u00d7(10\u00d73.14+2\u00d710)=154.2\u5398\u7c73
\u4e0d\u61c2\u53ef\u8ffd\u95ee\uff0c\u6709\u5e2e\u52a9\u8bf7\u91c7\u7eb3\uff0c\u8c22\u8c22\uff01
答至少要用铁丝17.99分米
3.5π+14分米 ≈25分米。
绛旓細鐢ㄩ搧涓濇妸涓ゆ牴鍚屾牱绮楃殑閾佺鎹3鍦,閽㈢澶栫洿寰勬槸40鍘樼背 ,濡傛灉閾佷笣鐨勬帴澶撮暱搴﹀拷鐣ヤ笉璁,鑷冲皯闇瑕佸闀匡紵瑙ｏ紝寰楋細鍒嗘瀽锛鎹嗕竴鍦堢敤閾佷笣鐨勯暱搴︾瓑浜庣洿寰29鍘樼背鐨勫渾鐨勫懆闀垮姞涓婁袱鏉＄洿寰勭殑闀垮害锛屾牴鎹渾3鐨勫懆闀垮叕寮忥細c=蟺d锛屾眰鍑烘崋涓鍦堢殑闀垮害鍐嶄箻2鍗冲彲 锛3.14脳40+40脳3锛壝3锛=锛125.6+120锛壝3锛=245....
绛旓細3*锛10+10+3.14*10锛=154.2鍘樼背
绛旓細锛10x3.14+10x2锛墄3 =(31.4+20)x3 =51.4x3 =154.2绫 ~濡傛灉浣犺鍙垜鐨勫洖绛旓紝璇峰強鏃剁偣鍑汇愰噰绾充负婊℃剰鍥炵瓟銆戞寜閽畘~鎵嬫満鎻愰棶鑰呭湪瀹㈡埛绔彸涓婅璇勪环鐐广愭弧鎰忋戝嵆鍙倊浣犵殑閲囩撼鏄垜鍓嶈繘鐨勫姩鍔泘~~濡傝繕鏈夋柊鐨勯棶棰橈紝璇蜂笉瑕佽拷闂殑褰㈠紡鍙戦侊紝鍙﹀鍙戦棶棰樺苟鍚戞垜姹傚姪鎴栧湪杩介棶澶勫彂閫侀棶棰橀摼鎺ュ湴鍧锛岀瓟棰樹笉...
绛旓細搴旇鏄渶鐭惂 閽笣瑕侊紙2涓½涓閽㈢鎴潰鐨勫懆闀+2涓挗绠℃埅闈㈢洿寰劽2锛夌殑3鍊 搴旀槸锛½10蟺+2脳10脳10锛壝3=15蟺+600 cm
绛旓細2*3.14*10+10*4=62.8+40=102.8
绛旓細鏄洿寰5鍘樼背鐨勯挗绠鍚.閭ｅ氨鏄涓や釜閽㈢鐩镐氦鎺掑垪 鐢ㄧ殑閾佷笣闀垮害涓鍦堢瓑浜庝竴涓挗绠＄殑鍛ㄩ暱+2鍊嶉挗绠＄洿寰 鎵浠ラ搧涓濋暱搴=2锛5蟺+2*5锛=10蟺+20 绾︾瓑浜51.4
绛旓細锛20x2+3.14x20锛墄2 =锛40+62.8锛墄2 =102.8x2 =205.6鍘樼背
绛旓細鑷冲皯闇瑕102.8鍘樼背閾佷笣銆
绛旓細鎹嗙粦涓ゆ牴閽㈢锛屼竴鍦堢殑闀垮害锛岀瓑浜庝竴涓挗绠″渾鍛ㄩ暱锛屽啀鍔犱笂2娈甸挗绠＄殑鐩村緞銆傛墍浠ワ紝涓鍦堥暱搴 = 蟺D+2D = 3.14脳20+2脳20 = 102.8 鍘樼背銆4鍦堢殑闀垮害 = 102.8脳4 = 411.2 鍘樼背銆
绛旓細闇瑕=3脳(10脳3.14+2脳10)=154.2鍘樼背 涓嶆噦鍙拷闂紝鏈夊府鍔╄閲囩撼锛岃阿璋紒
