下图的梯形abcd中,ad
△ABE∽△DAF，△DAF∽△GAE，△ABE∽△GAE，证明如下：∵在梯形ABCD中，AD∥BC，AB=AD=CD，
∴∠BAD=∠ADC，
∵DE=CF，
∴AE=DF，
∴△ABE≌△DAF，
即△ABE∽△DAF，
∴∠ABE=∠DAF，
∵∠AEB=∠GEA，
∴△ABE∽△GAE，
∴△ADF∽△GAE．
绛旓細瑙ｏ細杩囩偣E浣淓M骞宠浜嶢B锛屼氦BC浜庣偣M锛岃繃鐐笶浣淓N骞宠浜嶤D锛屼氦BC浜庣偣N 鈭碋M//AB锛孍N//CD 鈭粹垹EMN=鈭燗BC锛屸垹ENM=鈭燘CD 鈭碘垹ABC鍜屸垹BCD浜掍綑 鈭粹垹ABC+鈭燘CD=90掳 鈭粹垹EMN+鈭燛NM=90掳 鈭粹垹MEN=90掳 鈭粹柍EMN涓虹洿瑙掍笁瑙掑舰 鈭AD//BC锛孍M//AB锛孍N//CD 鈭村洓杈瑰舰ABME涓嶤DEN涓哄钩琛屽洓杈瑰舰 ...
绛旓細绛旓細鍏堢敾姊舰ABCD鐨勫瀭鐩寸嚎涓篊F 鍒欐褰㈢殑闈㈢Н涓(BC+AD)*CF/2 鐢籈G鍨傜洿浜AD锛鑰孍涓篊D鐨勪腑鐐癸紝鍙互寰楀埌EG=CF/2 涓夎褰DE鐨勯潰绉负AD*EG/2=AD*CF/4 宸茬煡姊舰闈㈢Н涓66骞虫柟鍘樼背锛屼笖AD=2BC锛屽緱鍒帮紙AD+BC锛*CF/2=3AD*CE/4=66 鍒欎笁瑙掑舰鐨勬缁揂D*CF/4=(3AD*CE/4)/3=66/3=22骞虫柟鍘樼背...
绛旓細鍒濅腑鍑犱綍閮戒涪浜嗗緢澶氬勾浜嗭紝涔熻鎴戠殑璁＄畻杩囩▼姣旇緝澶嶆潅銆傝В锛氣埖AD鈭C AB=CD 鈭姊舰ABCD涓虹瓑鑵版褰 鈭粹垹ABC=鈭燚CB 鈭燘AD=鈭燙DA 鈭礎B=CD BC鍏辫竟 鈭粹柍ABC鈮屸柍DCB 鈭粹垹DBC=鈭燗CB 鈭燘AC=鈭燙DB 鍙堚垹BAD=鈭燙DA 鈭粹垹OAD=鈭燨DA 鍙圓C鈯D 鈭粹柍AOD鍜屸柍BOC涓虹瓑鑵扮洿瑙掍笁瑙掑舰 鈭礎D=3锛屾牴鎹嬀鑲...
绛旓細濡傚浘浣滆緟鍔╃嚎 DE鈥朅C 锛屼氦 BC 鐨勫欢闀跨嚎浜 E 鍦ㄨ繖涓姊舰涓 AD鈥朆C锛屽嵆 AD鈥朇E ,鑰 DE 鍙堝钩琛屼簬 AC锛屾墍浠ュ厛璇佹槑 鍥涜竟褰DCE 鏄钩琛屽洓杈瑰舰锛屽洜涓篈DCE鏄钩琛屽洓杈瑰舰锛屾墍浠 AC=DE=8cm銆丄D=CE锛屾墍浠C+CE=BE=BC+AD 娉ㄦ剰鈻矪DE鏄洿瑙掍笁瑙掑舰锛屼笖鎴戜滑宸茬粡鐭ラ亾 AC=DE=8cm銆丅D=6cm ,浜庢槸鎴戜滑鍙互...
绛旓細鍑嗗宸ヤ綔锛氳繛MC,MD,杩嘙浣滄褰㈢殑楂楪H,璁AD=x锛屽垯BC=2x,璁綠H=5h 鍒欐槗寰 MH=3h锛孧G=2h 鍑犱釜纭畾鐨勫硷細S姊舰ABCD=(x+2x)脳5h/2=7.5xh S鈻矨MD=AD脳MH/2=3hx/2 S鈻矼BC=BC脳MG/2=2hx 1銆佸綋S鍥涜竟褰MND:S鍥涜竟褰CNM=3锛1 鈭碨鍥涜竟褰MND=7.5xh脳3/4=45xh/8 S鍥涜竟褰CNM...
绛旓細璇曢鍒嗘瀽锛氬姩鐐筆浠庣偣A鍑哄彂锛屼互1cm/s鐨勯熷害娌跨潃A鈫払锛岀敱鍥锯憽鐭ュ綋P鐐瑰湪B鐐规椂鍊欙紝鈻砅AD鐨勯潰绉疭= = 锛涘湪姊舰ABCD涓紝AD鈭C锛屸垹A=60掳锛岀敱鍥锯憽鐭鐐逛粠A鈫払鐢ㄤ簡2绉掞紝鎵浠B=2锛宧=AB = 锛屽嵆 锛孉D=6锛涚偣P鐢盉鈫扖锛岀敱鍥锯憽鐭ワ紝鎵鐢ㄦ椂闂翠负2绉掞紝BC=2锛屾墍浠B="BC" 锛屽湪姊舰ABCD...
绛旓細锛1锛8锛2锛 锛1锛夊欢闀緼M浜C鐨勫欢闀跨嚎浜庣偣N锛 鈭AD鈭C锛屸埓鈭燚AM=鈭燦锛屸垹D=鈭燤CN锛屸埖鐐筂鏄竟CD鐨勪腑鐐癸紝鈭碊M=CM锛屸埓鈻矨DM鈮屸柍NCM锛圓AS锛夛紝鈭碈N=AD=3锛孉M=MN= AN锛屸埓BN=BC+CN=5+3=8锛屸埖鈭燗BC=90掳锛屸埓S 鈻 ABN = 脳AB?BN= 脳4脳8=16锛屸埓S 鈻 ABM = S ...
绛旓細64 鍒嗘瀽锛氬畠浠殑楂樼浉鍚岋紝绌虹櫧閮ㄥ垎鐨勫簳涓16锛屽彲寰楅珮涓40*2/10=8锛屽垯娑傝壊閮ㄥ垎闈㈢Н涓16*8/2=64
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绛旓細锛1锛変竴瀹氭槸骞宠鍥涜竟褰 杩炴帴姊舰瀵硅绾緽D 鍥犱负E H G F 鏄洓杈圭殑涓嚎 鎵浠H骞宠涓旂瓑浜庝簩鍒嗕箣涓BD GF骞宠涓旂瓑浜庝簩鍒嗕箣涓BD 鎵浠H骞宠涓旂瓑浜嶨F 鏍规嵁骞宠鍥涜竟褰㈢殑鍒ゅ畾瀹氱悊鎵浠ュ緱鍑哄畠涓哄钩琛屽洓杈 锛2锛夋坊鍔犵殑鏉′欢鏄疉B=DC 褰揂B=DC鏃姊舰ABCD灏变负绛夎叞姊舰 鎵浠ヨBAD=瑙扐DC 鍙堝洜涓篈E=DG AH=DH 鎵浠...
