长方形已知边长，怎么求周长和面积 已知一个长方形的周长和边长，怎么求面积
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\u5df2\u77e5\u957f\u65b9\u5f62\u9762\u79ef\u548c\u5bbd\uff0c\u90a3\u4e48
\u957f\u65b9\u5f62\u7684\u957f=\u9762\u79ef/\u5bbd
\u5957\u5165\u8fb9\u957f\u516c\u5f0f\u5373\u53ef\u3002
\u4f8b\u5982\u5df2\u77e5\u957f\u65b9\u5f62\u9762\u79ef\u548c\u5bbd\u5206\u522b\u4e3a12\u548c3\uff0c
\u90a3\u4e48\u957f\u65b9\u5f62\u7684\u957f=12/3=4
\u8fb9\u957f=\uff084+3\uff09\u00d72=14
\u6269\u5c55\u8d44\u6599\uff1a
\u9762\u79ef\u8ba1\u7b97
\u957f\u65b9\u5f62(\u77e9\u5f62\uff09\uff1a
{\u957f\u65b9\u5f62\u9762\u79ef=\u957f\u00d7\u5bbd}
\u6b63\u65b9\u5f62\uff1a
{\u6b63\u65b9\u5f62\u9762\u79ef=\u8fb9\u957f\u00d7\u8fb9\u957f}
\u5e73\u884c\u56db\u8fb9\u5f62\uff1a
{\u5e73\u884c\u56db\u8fb9\u5f62\u9762\u79ef=\u5e95\u00d7\u9ad8}
\u4e09\u89d2\u5f62\uff1a
{\u4e09\u89d2\u5f62\u9762\u79ef=\u5e95\u00d7\u9ad8\u00f72}
\u68af\u5f62\uff1a
{\u68af\u5f62\u9762\u79ef=\uff08\u4e0a\u5e95+\u4e0b\u5e95\uff09\u00d7\u9ad8\u00f72}
\u5706\u5f62\uff08\u6b63\u5706\uff09\uff1a
{\u5706\u5f62\uff08\u6b63\u5706\uff09\u9762\u79ef=\u5706\u5468\u7387\u00d7\u534a\u5f84\u00d7\u534a\u5f84}
\u5706\u73af\uff1a
{\u5706\u5f62\uff08\u5916\u73af\uff09\u9762\u79ef={\u5706\u5468\u7387\u00d7\uff08\u5916\u73af\u534a\u5f84^2-\u5185\u73af\u534a\u5f84^2\uff09}
\u6247\u5f62\uff1a
{\u5706\u5f62\uff08\u6247\u5f62\uff09\u9762\u79ef=\u5706\u5468\u7387\u00d7\u534a\u5f84\u00d7\u534a\u5f84\u00d7\u6247\u5f62\u89d2\u5ea6/360}
\u957f\u65b9\u4f53\u8868\u9762\u79ef\uff1a
{\u957f\u65b9\u4f53\u8868\u9762\u79ef=\uff08\u957f\u00d7\u5bbd+\u957f\u00d7\u9ad8+\u5bbd\u00d7\u9ad8\uff09\u00d72}
\u6b63\u65b9\u4f53\u8868\u9762\u79ef\uff1a
{\u6b63\u65b9\u4f53\u8868\u9762\u79ef=\u68f1\u957f\u00d7\u68f1\u957f\u00d76}
\u7403\u4f53\uff08\u6b63\u7403\uff09\u8868\u9762\u79ef\uff1a
{\u7403\u4f53\uff08\u6b63\u7403\uff09\u8868\u9762\u79ef=\u5706\u5468\u7387\u00d7\u534a\u5f84\u00d7\u534a\u5f84\u00d74}
\u692d\u5706
(\u5176\u4e2d\u03c0(\u5706\u5468\u7387\uff0ca,b\u5206\u522b\u662f\u692d\u5706\u7684\u957f\u534a\u8f74\uff0c\u77ed\u534a\u8f74\u7684\u957f).
\u534a\u5706\uff1a
(\u534a\u5706\u5f62\u7684\u9762\u79ef\u516c\u5f0f=\u5706\u5468\u7387\u00d7\u534a\u5f84\u7684\u5e73\u65b9\u00f72\uff09
\u53c2\u8003\u8d44\u6599\u6765\u6e90\uff1a\u767e\u5ea6\u767e\u79d1-\u8fb9\u957f
\u53c2\u8003\u8d44\u6599\u6765\u6e90\uff1a\u767e\u5ea6\u767e\u79d1-\u9762\u79ef
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边长说的是正方形。周长=边长×4
面积=边长×边长
长方形：
周长=（长+宽）×2
面积=长×宽
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绛旓細include <stdio.h> include <stdlib.h> int main(){ float a,b,C,S;printf("璇疯緭鍏闀挎柟褰鐨勯暱\n");scanf("%f",&a);printf("璇疯緭鍏ラ暱鏂瑰舰鐨勫\n");scanf("%f",&b);C=(a+b)*2,S=a*b;printf("闀挎柟褰㈢殑鍛ㄩ暱鏄%f闈㈢Н鏄%f",C,S);return 0;} ...
绛旓細C=(8.5+4.2)涔2=25.4dm S=8.5涔4.2=35.7骞虫柟鍒嗙背
绛旓細闈㈢Н: S = 8 x 6 - 3.14 x 4² 梅 2 = 22.8 cm²鍛ㄩ暱锛欳 = 8 + 6 + 6 +3.14 x 8 梅 2 = 32.56 cm²
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绛旓細鍛ㄩ暱 (16+0.8)脳2=33.6 閭ｉ潰绉 16脳0.8=
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