如图，等腰梯形一腰的长为15厘米，上底比腰 短8厘米，求梯形的周长
\u5982\u56fe\uff0c\u7b49\u8170\u68af\u5f62\u4e00\u8170\u7684\u957f\u4e3a15\u5398\u7c73\uff0c\u4e0a\u5e95\u6bd4\u8170\u77ed8\u5398\u7c73\uff0c\u6c42\u68af\u5f62\u7684\u5468\u957f15\u00d72+\uff0815-8\uff09+\uff0815-8+3\u00d72\uff09\uff0c=30+7+\uff087+6\uff09\uff0c=37+13\uff0c=50\uff08\u5398\u7c73\uff09\uff0e\u7b54\uff1a\u68af\u5f62\u7684\u5468\u957f\u662f50\u5398\u7c73\uff0e
15\u00d72+\uff0815-8\uff09+\uff0815-8+3+3\uff09=50\uff08\u5398\u7c73\uff09
15×2+（15-8）+（15-8+3×2），=30+7+（7+6），
=37+13，
=50（厘米）．
答：梯形的周长是50厘米．
绛旓細璁姊舰鐨涓婂簳涓簒鍘樼背锛岄偅涔堜笅搴曚负锛坸+6锛夊帢绫筹紝x+锛6+x锛+15脳2=62锛 2x+6+30=62锛 2x+36=62锛 2x=26锛 x=13锛13+6=19锛堝帢绫筹級锛涚瓟锛氳繖涓褰㈢殑涓嬪簳闀夸负19鍘樼背锛
绛旓細72 - 15 脳 2 - 18 = 72 - 30 - 18 = 42 - 18 = 24锛坈m锛夌瓟锛氳繖涓绛夎叞姊舰鐨涓嬪簳鏄24鍘樼背銆
绛旓細浣犲ソ锛72-15脳2-18 =42-18 =24鍘樼背 濡傛灉瀵逛綘鏈夊府鍔╂湜閲囩撼銆
绛旓細绛夎叞姊舰锛岃叞闀鐩哥瓑 64锛(15脳2+14)=64锛44 =20(鍘樼背)涓嬪簳闀20鍘樼背銆
绛旓細鏍规嵁棰樻剰锛岃繖涓绛夎叞姊舰鐨涓嬪簳闀夸负55鍘樼背锛岃叞鏄25鍘樼背鎴 15鍘樼背銆傚綋鑵版槸25鍘樼背鏃讹紝涓婂簳涓15鍘樼背锛屽畠鐨勫懆闀夸负锛55+25+25+15=120锛堝帢绫筹級褰鑵伴暱鏄15鍘绫虫椂锛屼笂搴曚负25鍘樼背锛屽畠鐨勫懆闀夸负锛55+15+15+25=110锛堝帢绫筹級鎵浠ヨ繖涓褰㈢殑鍛ㄩ暱鏄120鍘樼背鎴110鍘樼背銆
绛旓細锛50-20锛壝2 =30梅2 =15锛堝帢绫筹級绛旓細姣忎竴鏉鑵伴暱15鍘绫筹紟鏁呯瓟妗堜负锛15锛
绛旓細鈶犺叞闀夸负25鍘樼背鏃讹細55+25脳2+15=55+50+15=120鍘樼背锛涒憽鑵伴暱涓15鍘绫虫椂锛屼袱搴曟槸55鍘樼背銆25鍘樼背锛屾棤娉曟瀯鎴绛夎叞姊舰锛涓嶇鍚堥鎰忥紟鏁呯瓟妗堜负锛25锛
绛旓細杩欎釜鏈変笁绉嶆儏鍐 15cm鏄叞锛11cm鏄叞 锛 14cm鏄叞 鍛ㄩ暱鍒嗗埆鏄細11+14+15*2 锛 55锛坈m锛14+15+11*2 锛 51锛坈m锛11+15+14*2 锛 54锛坈m锛
绛旓細涓婂簳15鍘绫 涓嬪簳鍒欐槸35鍘樼背 鎵浠绛夎叞姊舰鍛ㄩ暱=涓婂簳+涓嬪簳+2脳鑵伴暱 =15+35+2脳15 =80鍘樼背
绛旓細涓涓绛夎叞姊舰鐨鍛ㄩ暱鏄68鍘樼背锛屼笂涓嬪簳涔嬪拰鏄38锛堝帢绫筹級锛屽畠鐨勪竴鏉¤叞闀匡紙15锛夊帢绫筹紝锛68-38锛/2 =15锛堝帢绫筹級
