已知长方形的周长是16.28dm,求圆的面积和周长各是多少？（在线等，大佬们） 长方形的面积等于圆的面积，已知长方形的周长是16.56厘米．...
\u56fe\u4e2d\u5706\u4e0e\u957f\u65b9\u5f62\u7684\u9762\u79ef\u76f8\u7b49\uff0c\u957f\u65b9\u5f62\u957f6.28dm\uff0c\u9634\u5f71\u90e8\u5206\u7684\u9762\u79ef\u548c\u5468\u957f\u5404\u662f\u591a\u5c11\uff1f\u671b\u91c7\u7eb3\uff01\uff01\uff01
\u8bbe\u5706\u534a\u5f84\u4e3aR\uff0c\u5219
\u5706\u9762\u79ef=\u77e9\u5f62\u9762\u79ef\uff1a3.14 x R x R = 6.28 x R
\u89e3\u5f97R=2
\u9634\u5f71\u9762\u79ef=\u77e9\u5f62\u9762\u79ef\u20141/4\u5706\u9762\u79ef=3 x 3.14=9.42\uff08\u5e73\u65b9\u5206\u7c73\uff09
\u9634\u5f71\u5468\u957f=1/4\u5706\u5468\u957f+\u77e9\u5f62\u5468\u957f\u20142 x \u5706\u534a\u5f84=15.7\uff08dm\uff09
\u56e0\u4e3a\u03c0r2=\uff08a+r\uff09r\uff0c\u5219\u03c0r=a+r\uff0ca=\u03c0r-r\u2460\uff0c\u53c8\u56e0\uff08a+2r\uff09=16.56\u00f72\uff0c\u5219a=16.56\u00f72-2r\uff0c\u5373a=8.28-2r\u2461\uff1b\u5c06\u2461\u4ee3\u5165\u2460\u5f97\uff1a \u03c0r-r=8.28-2r\uff0c \u03c0r+r=8.28\uff0c \uff08\u03c0+1\uff09r=8.28\uff0c\uff083.14+1\uff09r=8.28\uff0c 4.14r=8.28\uff0c r=2\uff1ba=8.28-2\u00d72=4.28\uff08\u5398\u7c73\uff09\uff1b\u9634\u5f71\u90e8\u5206\u7684\u5468\u957f\uff1a16.56-2\u00d72+2\u00d73.14\u00d72\u00d714\uff0c=12.56+3.14\uff0c=15.7\uff08\u5398\u7c73\uff09\uff1b\u9634\u5f71\u90e8\u5206\u7684\u9762\u79ef\uff1a3.14\u00d722\u00d734\uff0c=3.14\u00d74\u00d734\uff0c=3.14\u00d73\uff0c=9.42\uff08\u5e73\u65b9\u5398\u7c73\uff09\uff1b\u7b54\uff1a\u9634\u5f71\u90e8\u5206\u7684\u5468\u957f\u662f15.7\u5398\u7c73\uff0c\u9762\u79ef\u662f9.42\u5e73\u65b9\u5398\u7c73\uff0e
解：这道题可能输入有问题，因为已知长方形的周长而没有长与宽的比，不能确定长方形的形状和大小，所以这个图形应是正方形，边长为16.28/4=4.07dm
正方形内切圆半径为
4.07/2=2.035
周长=3.14x4.07=12.7798dm
面积=3.14x2.035^2
≈13dm^2
绛旓細2(r+3.14*r)=16.28 8.14r=16.28 r=2 cm S=3.14*2^2=12.56 cm2 鑷繁鎯虫兂鍏崇郴鍚
绛旓細闀挎柟褰闈㈢Н:4脳3=12骞虫柟鍒嗙背 鍦嗗崐寰:4梅2=2鍒嗙背 鍗婂渾闈㈢Н:2脳2脳3.14梅2=6.28骞虫柟鍒嗙背 鍓╀笅閮ㄥ垎绾哥墖闈㈢Н:12-6.28=5.72骞虫柟鍒嗙背 闀挎柟褰㈠懆闀:(4+3)脳2=14鍒嗙背 鍗婂渾鐨勫懆闀:4脳3.14梅2=6.28鍒嗙背 鍓╀笅閮ㄥ垎绾哥墖鐨勫懆闀:14-4+6.28=16.28鍒嗙背 ...
绛旓細杩欎釜鍥惧舰鐨勫懆闀鐢变袱涓崐鍦嗗拰闀挎柟褰㈢殑涓ゆ潯鐩寸嚎缁勬垚鐨勶紝涓や釜鍗婂渾缁勬垚涓涓渾锛屽懆闀=蟺d=6.28锛屾墍浠ュ懆闀=6.28+5+5=16.28
绛旓細鍒嗘瀽锛氳鍦嗘煴渚ч潰灞曞紑锛屽簳闈鍛ㄩ暱鍗虫槸杩欎釜闀挎柟褰㈢殑闀挎垨鑰呭锛屾墍浠ユ牴鎹鎰忎細寰楀嚭2涓瓟妗堛傜敱浜庡渾鏌变晶闈㈢Н灏辨槸杩欎釜闀挎柟褰㈢殑闈㈢Н銆傞暱鏂瑰舰鐨勯潰绉=闀棵楀銆傚渾鏌辩殑渚ч潰绉叕寮忔槸2蟺rh锛宧鏄渾鏌辩殑楂樸傝В锛氳杩欎釜鍦嗘煴鐨勫簳闈㈠崐寰勬槸r锛屽洜涓哄渾鏌辩殑渚ч潰绉=2蟺rh銆傛墍浠 褰16.28涓搴曢潰鍦嗗懆闀挎椂锛岃鍦嗘煴鐨勯珮灏...
绛旓細鍥1鍛ㄩ暱=浠10涓虹洿寰勭殑2涓崐鍦嗙殑鍛ㄩ暱+闀40瀹10鐨闀挎柟褰㈢殑鍛ㄩ暱-2*闀挎柟褰㈢殑瀹=浠10涓虹洿寰勭殑鍦嗙殑鍛ㄩ暱+2*闀挎柟褰㈢殑闀=蟺*10+2*40=10蟺+80=10*3.14+80=11.4绫 鍥2鍛ㄩ暱=浠4涓虹洿寰勭殑鍗婂渾鐨勫懆闀+2*3+4=4蟺/2+6+4=2蟺+10=2*3.14+10=16.28绫 ...
绛旓細闃村奖閮ㄥ垎鍛ㄩ暱=姝鏂瑰舰鍛ㄩ暱+鍦嗗懆闀 锛3+2锛壝2+3.14脳2 =10+6.28 =16.28锛堝帢绫筹級
绛旓細鎵浠ヨ繖涓渾鏌卞簳闈鐨勫懆闀灏辨槸18.84cm 鍛ㄩ暱=2*3.14*鍗婂緞 鎵浠ュ崐寰勬槸3cm
绛旓細5*2鏄袱杈圭殑闀垮害锛2蟺r鏄袱杈瑰崐鍦鐨勫懆闀5*2=10 蟺=3.14 鍥犱负闀挎柟褰㈢殑瀹芥槸鍦嗙殑鐩村緞锛岄偅涔堝崐寰勫氨鏄25涔樹互2+3.14涔樹互2鍐嶄箻浠2锛堝崐寰勶級銆傜粨鏋滄槸22.56鍘樼背
绛旓細闈㈢Н鏄細3.14脳2^2=12.56.鍛ㄩ暱鏄3+3+4+3.14脳2=16.28
绛旓細鍒嗘瀽 鍓╀綑闈㈢Н锛岀敤闀挎柟褰闈㈢Н-鍗婂渾闈㈢Н锛3脳4-蟺脳2脳2脳1/2=12-2蟺=12-6.28=5.72骞虫柟鍘樼背 鍓╀綑绾哥墖鐨勫懆闀鐢变笁娈电嚎娈碉紙4鍘樼背鐨勪竴鏉★紝3鍘樼背鐨勪袱鏉★級鍜岀洿寰4鍘樼背鐨勫渾鍛ㄩ暱鐨勪竴鍗婄粍鎴愩傚懆闀=4+3*2+4*3.14/2=16.28鍘樼背
