已知一个长方形的周长是24.84分米，求这个圆形的面积是多少平方分米？ 推倒圆，把这个圆形分成若干份拼成一个长方形，己知长方形的周长...
\u5df2\u77e5\u8fd9\u4e2a\u957f\u65b9\u5f62\u7684\u5468\u957f\u662f24.84\u5206\u7c73\uff0c\u6c42\u8fd9\u4e2a\u5706\u5f62\u7684\u9762\u79ef\u662f\u591a\u5c11\u5e73\u65b9\u5206\u7c73\uff1f3.14*d+d=24.84d=6,r=3\u5706\u5f62\u7684\u9762\u79ef=3*3*3.14=28.26\u5e73\u65b9\u5206\u7c73\u8ffd\u95ee\uff1a\u4e3a\u6bdb\u8fd9\u6837\u505a\u8865\u5145\uff1a\u89e3\uff1a\u8bbe\u957f\u65b9\u5f62\u7684\u5bbd\uff08\u4e5f\u5c31\u662f\u5706\u7684\u534a\u5f84\uff09\u662fX\uff0c\u957f\u65b9\u5f62\u7684\u957f\u5c31\u662f3.14\uff083.14X+X\uff09*2=24.844.14X=12.42 X=33*3*3.14=28.26\u8ffd\u95ee\uff1a\u8c22\u5566\uff0c\u4e48\u4e48
2\u03c0R\uff0b2R\uff1d24.848.28R\uff1d24.84R\uff1d3\ufe59\u5206\u7c73\ufe5a\u5706\u7684\u9762\u79ef\u662f 3.14\u00d73\u00d73\uff1d28.26\ufe59\u5e73\u65b9\u5206\u7c73\ufe5a
49.18
49.18
3.14*3*3=28 .26
46•3
绛旓細鍒嗘瀽锛氳繖涓闀挎柟褰㈠懆闀跨瓑浜鍦鐨勫懆闀鍔犱笂2鍊嶅渾鐨勫崐寰勶紝鍗2蟺R+2R=24.8, R=12.4/(蟺+1锛夛紱闈㈢Н=蟺R2=12.42蟺/(蟺+1)2鈮埪仿
绛旓細鎶涓涓鍦嗗钩鍧囧垎鎴愯嫢骞蹭釜灏忔墖褰紝鍐嶆嫾鎴愪竴涓繎浼肩殑闀挎柟褰紝杩欎釜闀挎柟褰㈢殑 闀 鏄崐鍛ㄩ暱 = 9.42鍒嗙背 瀹 鏄崐寰 = (24.84 / 2) - 9.42 = 3鍒嗙背 鍥犳 鍦鐨勫懆闀 = 闀 x 2 = 9.42 * 2 = 18.84 鍒嗙背 鍦嗛潰绉 = 闀挎柟褰㈤潰绉 = 9.42 x 3 = 28.26 骞虫柟鍒嗙背 ...
绛旓細涔熸槸
绛旓細鎴戠粰浣犵瓟妗堬紝浣犺绛夋垜
绛旓細2脳(9.3+3.1)=2脳12.4 =24.8 鍛ㄩ暱鏄24.8绫炽
绛旓細鍕捐偂瀹氱悊锛氬簳^2+楂榐2=鏂滆竟^2 6*6+8*8=100 10*10=100 瀹=涓夎褰㈤潰绉/闀 6*8/2/10=2.4(cm)锛2.4+10锛*2 =12.4*2 =24.8锛坈m)绛旓細闀挎柟褰㈠懆闀24.8鍘樼背銆
绛旓細闀挎柟褰㈢殑鍛ㄩ暱鏄24.8绫筹紝闀挎柟褰㈢殑瀹芥槸3.14绫筹紝閭ｄ箞姝ｆ柟褰㈢殑闀挎槸9.66绫
绛旓細涓涓姝鏂瑰舰鐨勫懆闀挎槸24.8绫筹紝瀹冪殑杈归暱=24.8梅4=6.2锛堢背锛夊畠鐨勯潰绉=6.2²=38.44锛堝钩鏂圭背锛
绛旓細姝鏂瑰舰鐨杈归暱鏄24.8梅4=6.2(m)6.2脳6.2=38.44(m²)杩欎釜姝ｆ柟褰㈢殑闈㈢Н鏄38.44骞虫柟绫炽
绛旓細鎷煎悗鐨闀挎柟褰㈢殑鐭竟鏄渾鐨勫崐寰勶紝鎷煎悗鐨勯暱杈规槸鍦嗙殑鍛ㄩ暱鐨勪竴鍗婏紝灏辨槸3.14*R锛屽緱鍒扮殑鎬诲懆闀=6.28R+2R锛屽師鏈夌殑鍦鐨勫懆闀挎槸6.28R锛屾墍浠ュ鍔犵殑2鍘樼背锛屽彲浠ョ畻鍑哄崐寰勪负1cm,杩欎釜鍦嗙殑鍛ㄩ暱鑲畾鏄6.28cm,闈㈢Н鏄3.14cm2
