如图所示,已知三角形ABC的内角和是180度,你能说明角1+角2+角3=360度吗?
绛旓細杩炴帴EC锛屽洜涓衡垹1+鈭2+鈭燗CE+鈭燘CE=360銆-鈭燗EC-鈭燘EC=鈭燗EB 鎵浠モ垹1+鈭2+鈭燙=鈭燗EB 濡傛灉涓嶄細鍙互鐩存帴鍦ㄧ彮涓婇棶鎴
绛旓細鈭粹垹CAB=鈭燙BA=45掳;鍙堚垹CAD=鈭燙BD=15掳.鈭粹垹DAB=鈭燚BA=30掳,鍒橠A=DB;鈭燘DE=60掳.鈭礎C=BC,DA=DB,鈭燙AD=鈭燙BD.鈭粹娍CAD鈮屸娍CBD(SAS),鈭燗CD=鈭燘CD=45掳.鍒欌垹CDE=鈭燙AD+鈭燗CD=60掳 =鈭燘DE.鏁匘E骞冲垎鈭燘DC.(2)鈭碘垹CDE=60掳(宸茶瘉);DC=DM(宸茬煡).鈭粹娍CDM涓虹瓑杈涓夎褰,CM=CD;鈭...
绛旓細濡傛灉涓嶅樊鏉′欢鐨勮瘽DEFG鏄钩琛屽洓杈瑰舰浣嗕笉涓瀹氭槸鐭╁舰銆傗憼鏄钩琛屽洓杈瑰舰锛氱敱涓夎褰涓綅绾垮畾涔夊彲鐭E涓衡柍BPC涓BC鐨涓綅绾匡紝FG涓衡柍ABC涓瑽C鐨勪腑浣嶇嚎锛岀敱涓夎褰腑浣嶇嚎鎬ц川鏈塂E鈭C涓旈暱搴︿负BC鐨勪竴鍗婏紝FG鈭C涓旈暱搴︿负BC鐨勪竴鍗娿傛墍浠E銆丗G骞宠涓旂浉绛夛紝鎵浠EFG鏄钩琛屽洓杈瑰舰銆傗憽涓嶄竴瀹氭槸鐭╁舰锛氬厛鍋囪鏄煩褰...
绛旓細瑙ｏ細鈭礎E骞冲垎鈭燘AC锛孉F骞冲垎鈭燙AD 鈭粹垹EAF=鈭燛AC+鈭燙AF=1/2(鈭燘AC+鈭燙AD)=90掳 鈭粹柍EAF鏄洿瑙涓夎褰 鈭碘垹ACB-鈭燘=90掳 鈭粹垹BAC=180掳-鈭燗CB-鈭燘=180掳-(90掳+鈭燘)-鈭燘=90掳-2鈭燘 鈭粹垹BAE=1/2鈭燘AC=45掳-鈭燘 鈭粹垹AEC=鈭燘AE+鈭燘=45掳 鈭粹柍EAF鏄瓑鑵扮洿瑙掍笁瑙掑舰 ...
绛旓細鍥炵瓟锛氳繛鎺O,BO,CO,鍥犱负O鏄唴鍒囧渾鍦嗗績,鎵浠O,BO,CO鏄骞冲垎绾,鏄撹瘉涓夎褰鍏ㄧ瓑,鎵浠ラ偅浜涘皬涓夎褰㈤潰绉浉绛 鎵浠ヤ笁瑙掑舰闈㈢Н=6=2(0.5AE*r+0.5CD*r+0.5BF*r) 鎵浠=1 婊℃剰璇烽噰绾,涓嶆噦璇疯拷闂,璋㈣阿
绛旓細杩欎釜棰樼洰鍙互鐢ㄥ叏绛涓夎褰鏉ヨ瘉鏄庛備綔鍥惧涓嬶細宸茬煡锛欰B=AC锛孫B=OC 杩炴帴AO浜C浜嶥鐐 鈻矨OB鈮屸柍AOC锛堜笁杈癸級鎵浠ワ細鈭燘AO=鈭燙AO锛屸垹BOD=鈭燙OD 鎵浠モ柍BOD鈮孋OD锛屸垹BDO=鈭燙DO 鐢辨寰楀埌AD鈯C
绛旓細h1+h2+h3=h 銆傝瘉鏄庯細杩炴帴PA銆丳B銆丳C锛屽垯涓夎褰BC琚垝鍒嗘垚涓変釜涓夎褰AB銆丳BC銆丳CA 锛岃涓夎褰㈣竟闀夸负 a 锛屽垯 SABC=1/2*ah 锛岃 SPAB+SPBC+SPCA=1/2*ah1+1/2*ah2+1/2*ah3=1/2*a(h1+h2+h3) 锛岀敱浜 SABC=SPAB+SPBC+SPCA 锛屽洜姝 鍙緱 1/2*a(h1+h2+h3)=1/2*ah 锛屾墍浠...
绛旓細瑙 瑙払AP=60-瑙払AP 瑙扖AP=60-瑙払AP 鍙圓B=AC 鎵浠涓夎褰AP1B鍏ㄧ瓑APC
绛旓細杩嘇浣淎M鈯C锛屼氦BC浜嶮锛屼氦DG浜嶯锛濡傚浘鎵绀锛氣埖鍥涜竟褰EFG涓烘鏂瑰舰锛屸埓DG鈭C锛孌E=EF=FG=DG锛屸埓鈭燗DG=鈭燘锛屸垹AGD=鈭燙锛孉N鈯G锛屸埓鈻矨DG鈭解柍ABC锛岃DE=EF=FG=DG=x锛屽張鈻矨BC涓鸿竟闀夸负3鐨勭瓑杈涓夎褰锛孉M鈯C锛屸埓M涓BC鐨涓偣锛屽嵆BM=CM=12BC=32锛屽湪Rt鈻矨BM涓锛屾牴鎹鍕捐偂瀹氱悊寰楋細AM=AB2...
绛旓細2鈭3/3
