张爷爷用篱笆围一块一面靠墙的梯形菜地，如图。已知篱笆全长35米，这块菜地的面积是多少平方米? 6题 ，张爷爷用篱笆围块一面靠墙的梯形菜地（如图）。已知篱笆...
\u7528120\u7c73\u957f\u7684\u7bf1\u7b06\u56f4\u4e00\u5757\u83dc\u5730\u8fd9\u5757\u83dc\u5730\u5bbd\u662f20\u7c73\u8fd9\u5757\u83dc\u5730\u957f\u591a\u5c11\u7c73\uff1f\u9762\u79ef\u591a\u5c11\u83dc\u5730\uff1f\u957f=120/2-20=40\u7c73\u3002
\u957f\u65b9\u5f62\u7684\u9762\u79ef=\u957f*\u5bbd=40*20=800\u5e73\u65b9\u7c73\u3002
\u8003\u70b9\uff1a\u957f\u65b9\u5f62\u3001\u6b63\u65b9\u5f62\u7684\u9762\u79ef\u3002
\u89e3\u9898\u65b9\u6cd5\uff1a\u6c42\u51fa\u957f\u65b9\u5f62\u83dc\u5730\u7684\u5bbd\uff0c\u518d\u6839\u636e\u957f\u65b9\u5f62\u7684\u9762\u79ef\u516c\u5f0f\u8fdb\u884c\u89e3\u7b54\u3002
\u6269\u5c55\u8d44\u6599\uff1a
\u76f8\u4f3c\u4f8b\u9898\uff1a
1\u3001\u6709\u4e00\u5757\u957f\u65b9\u5f62\u83dc\u5730\uff0c\u5b83\u8f83\u957f\u7684\u4e00\u6761\u8fb9\u9760\u7740\u5899\uff0c\u957f20\u7c73\uff0c\u7528\u7bf1\u7b06\u5c06\u8fd9\u4e2a\u83dc\u5730\u56f4\u8d77\u6765\u898140\u7c73\uff0e\u8fd9\u4e2a\u83dc\u5730\u7684\u9762\u79ef\u662f\u591a\u5c11\uff1f
\u5bbd\uff1a\uff0840-20\uff09\u00f72=20\u00f72=10\uff08\u7c73\uff09
\u9762\u79ef\uff1a20\u00d710=200\uff08\u5e73\u65b9\u7c73\uff09
2\u3001\u7237\u7237\u7528120\u7c73\u957f\u7684\u7bf1\u7b06\u56f4\u4e86\u4e00\u4e2a\u957f\u4e0e\u5bbd\u7684\u6bd43:2\u7684\u957f\u65b9\u5f62\u83dc\u5730,\u8fd9\u5757\u83dc\u5730\u7684\u9762\u79ef\u662f\u591a\u5c11?
\u957f\uff1a120\u00f72x3/\uff083+2\uff09=36\uff08\u7c73\uff09
\u5bbd\uff1a120\u00f72x2/\uff083+2\uff09=24\uff08\u7c73\uff09
\u9762\u79ef=\u957fx\u5bbd=36x24=864\uff08\u5e73\u65b9\u7c73\uff09
3\u3001\u7528120\u7c73\u957f\u7684\u7bf1\u7b06\u56f4\u6210\u4e00\u5757\u957f\u65b9\u5f62\u83dc\u5730,\u8981\u4f7f\u83dc\u5730\u7684\u957f\u662f\u5bbd\u76842\u500d,\u90a3\u4e48\u83dc\u5730\u7684\u957f\u548c\u5bbd\u5404\u662f\u591a\u5c11\uff1f
120/2=60\u7c73\uff0c60/(2+1)=20\u7c73\uff0c20*2=40\u7c73
\u6240\u4ee5\u957f40\u7c73\uff0c\u5bbd20\u7c73\u3002
\u68af\u5f62\u9762\u79ef\u7684\u516c\u5f0f\uff08\u4e0a\u5e95+\u4e0b\u5e95\uff09\u00d7\u9ad8\u00f72 \uff1b
\u90a38M\u5c31\u662f\u544a\u8bc9\u4f60\u9ad88M\uff0c\uff08\u4e0a\u5e95+\u4e0b\u5e95\uff09=35-8=27\uff1b
\u6700\u540e27\u00d78\u00f72=108\u68af\u5f62\u9762\u79ef\u7684\u516c\u5f0f\uff08\u4e0a\u5e95+\u4e0b\u5e95\uff09\u00d7\u9ad8\u00f72 \uff1b
\u90a38M\u5c31\u662f\u544a\u8bc9\u4f60\u9ad88M\uff0c\uff08\u4e0a\u5e95+\u4e0b\u5e95\uff09=35-8=27\uff1b
\u6700\u540e27\u00d78\u00f72=108\u68af\u5f62\u9762\u79ef\u7684\u516c\u5f0f\uff08\u4e0a\u5e95+\u4e0b\u5e95\uff09\u00d7\u9ad8\u00f72 \uff1b
\u90a38M\u5c31\u662f\u544a\u8bc9\u4f60\u9ad88M\uff0c\uff08\u4e0a\u5e95+\u4e0b\u5e95\uff09=35-8=27\uff1b
\u6700\u540e27\u00d78\u00f72=108
面积：1/2乘以27乘以8=108
绛旓細闈㈢Н锛1/2涔樹互27涔樹互8=108
绛旓細姊舰涓婁笅搴曚箣鍜岋細35-8=27m锛岄潰绉疭=27脳8梅2=108骞虫柟绫炽
绛旓細2涔8绛変簬16绫 35鍑16绛変簬19绫 19闄や互2绛変簬9.5绫 8涔9.5绛変簬76骞虫柟绫
绛旓細锛35-8锛墄8➗2=108
绛旓細姊舰鐨勯潰绉叕寮忔槸锛堜笂搴+涓嬪簳锛*楂/2 杩欓噷鏂滆竟鏄埧灞嬪澹侊紝姊舰楂=10绫筹紝绡辩瑔闀=涓婂簳+涓嬪簳+姊舰楂=35绫 鎵浠ヤ笂搴+涓嬪簳=绡辩瑔闀-姊舰楂=35-10=25 鎵浠ラ浮鍦洪潰绉嵆姊舰闈㈢Н=锛堜笂搴+涓嬪簳锛*楂/2=25*10/2=125骞虫柟绫
绛旓細瑙ｏ細绡辩瑔鍏ㄩ暱48绫筹紝姊舰楂15绫筹紝鍒欎笂涓嬪簳鐨勫拰鏄48-15=33绫炽傛褰㈤潰绉 = (涓婂簳+涓嬪簳)脳楂樏2 = 33脳15梅2 = 247.5 骞虫柟绫炽傛瘡骞虫柟绫虫敹鐧借彍9.5鍗冨厠锛屽垯涓鍏辨敹 9.5脳247.5 = 2351.25 鍗冨厠銆
绛旓細杩欓鏈夊浘锛屾病浼犲浘锛屽氨闅剧悊瑙ｉ鎰忎簡銆傚綋鏄竴涓洿瑙掓褰紝鑰屼笖澧欓潰鎵鍦ㄧ殑涓鏉¤竟鏄枩鐫鐨勶紝瀵归潰鐨勮竟鏄珮鏉ュ垪寮 35锛8锛27绫筹紝涓婂簳涓庝笅搴曠殑鍜 27脳8梅2锛108锕欏钩鏂圭背锕氾紝闈㈢Н鏄108骞虫柟绫
绛旓細48-15=33m 绠楀嚭姊舰鐨勫簳鍜岄珮鐨勫拰 33脳15梅2 =495梅2 =247.5(骞虫柟绫)绠楀嚭姊舰鐨勯潰绉 247.5脳9.5 =2351.25(鍗冨厠)绠楀嚭杩欏潡鍦颁竴鍏卞彲浠ユ敹鐧借彍2351.25鍗冨厠
绛旓細涓婂簳+涓嬪簳=45-15=30(绫)姊舰闈㈢Н涓 30脳15梅2=225(骞虫柟绫)鍙敹鐧借彍 225脳9.5=2137.5(鍗冨厠)
绛旓細璇ラ棶棰樺彲浠ヨ繖鏍锋潵鑰冭檻锛1銆侀暱60绫鐨勭绗鏄寚 鑿滃湴鐨勪袱涓鍜屼竴涓暱搴︾殑鍜岋紱2銆佹牴鎹暱鍜屽姣旓紝纭畾鑿滃湴鐨勫搴﹀拰闀垮害锛3銆佹渶鍚庤绠楄彍鍦伴潰绉疭=xy銆傝В锛氳鑿滃湴鐨勫搴﹀拰闀垮害鍒嗗埆涓簒銆亂锛屽垯鏈 y锛歺=2锛1 鈶 2x+y=60 鈶 瑙ｇ敱寮忊憼鍜屽紡鈶＄粍鎴愮殑鏂圭▼缁勶紝寰 x=15锛泍=30 鎵浠ワ紝鑿滃湴闈㈢Н涓 S=...
