Awuzange uzibuze ukuba ubume obunjani Isosceles unxantathu; Apha siza kuchaza yonke into ekufuneka uyazi malunga nayo, ekugqibeleni kweekhonsepthi ziya kucaca ngakumbi.

Isalathiso semixholo

## Isosceles unxantathu

Eli nani lejiyometri lelinye lezona zinto zilungeleleneyo ezikhoyo, linamacala amabini alinganayo nelinye elahlukileyo. Nokuba uthambekele kwii-engile zayo ezimbini ezilinganayo, ineempawu ezikhethekileyo kunye neempawu; ukuze sikubonise zonke iimpawu kunye nokubalulwa kweli nani linomdla.

Ngokuqulatha amacala amabini alinganayo ngobude nakwikona, ikuvumela ukuba uyixabise njengomfanekiso olinganayo ngokupheleleyo; ngokufanayo, isebenza njengesiseko samanye amanani ejiyometri; enokumisela into ethe kratya kuba ulingano lweeengile zalo luvumela olo khetho.

## Iimpawu zonxantathu ze-isosceles

Kwelinye icala, ineenkcukacha ezahlukileyo kunezabanye oontanga. Ukudityaniswa kukuvumela ukuba unikeze abo bafuna ezinye iindlela zokwenza amanye amanani, ke makhe sijonge ezinye zeempawu ezizodwa.

• Isiseko sinokuhluka kwaye amacala aso amabini aya kuhlala elingana kwi-angle kunye nobude.
• Inika ii-bisectors ezimbini ezilinganayo nesindululo esisekwe kwithiyori ye-Steiner-Lehmus.
• Amacala amabini ajongene namacala alinganayo ubukhulu becala angaphantsi kweedigri ezingama-90, kusetyenziswa le fomyula ilandelayo 2A + B = 180, enokuthi ithathelwe ingqalelo njengefomula efanayo A + B / 2 = 90, A ingaphantsi kwiidigri ezingama-90.
• Icandelo elihambelana nesiseko sonxantathu se-isosceles kunye neziphelo ezifanayo emacaleni kugqityiwe ukujonga unxantathu olingana nowokuqala.
• I-bisector kwisiseko sayo yeyee-symmetric axis kuphela, kuba ikwayi-bisector; ke lexantathu isosceles soze ilingane.
• Kwakhona i-bisector kwi-engile ye-vertex B iyahambelana nomgaqo 2A + B = 180, apho i-B ingaphantsi kwe-180 degrees, emva koko unxantathu uhlelwa ngeemeko ezibi, ezintathu kunye neemeko zokudakumba.

## Amahlelo

Lo nxantathu ubizwa ngokuba yi-isosceles enkosi kwigama lesiGrike "isosceles" apho "iso" lithetha ukulingana kunye no "Skelos" umlenze, eli gama lisetyenziselwa ukubhekisa kwelinye inani lejiyometri njenge-isosceles trapezoid efanayo unxantathu olinganayo i-isosceles kunye ne-scalene. Ngokwesiqhelo la macala mabini alinganayo abizwa ngokuba yimilenze kwaye icala elingalinganiyo libizwa ngokuba sisiseko; Ngokubhekisele kwii-engile, leyo yenziwa yimanyano yemilenze yomibini ibizwa ngokuba yi «vertex angle».

Ngokwenxalenye yabo, ii-angles ezenziwe kwisiseko zibizwa ngokuba "zii-angles ezisisiseko", i-vertex eveliswe kwicala eliphambi kwesiseko ibizwa ngokuba yincopho; Njengoko sibona, icandelo ngalinye linegama ngokweemeko ezithile, nangona kunjalo ingcali yezibalo yamaGrike egama linguEuclid, owayengowokuqala ukuyibiza ngokuba yi-isosceles.

Ukuze unxantathu ubekhona kwiisosceles kufuneka ngandlela ithile ityeke, ibe buhlungu okanye ithi nkqo. Ihlala ixhomekeke kwi "vertex angle"; Umzekelo ii-Euclides zathi isiseko asinakuqulatha ii-angles ze-obtuse (zingaphezulu kwamacala angama-90) kwaye zingabi zii-angles ezichanekileyo ezingama-90 degrees); oku kungakhokelela kwixabiso elingaphezulu kweedigri ezili-180 elingumlinganiselo opheleleyo walo naliphi na unxantathu.

Kwelinye iodolo, qaphela a Isosceles ekunxantathu, ngee-butuse okanye ii-engile ezilungileyo, umisela ukuba elinye lamacala alo lineedigri ezingama-90 okanye likhulu kuneedigri ezingama-90; Ngenxa yoko, i-isosceles angle ilungile, ifunyenwe, kwaye inzima kuphela ukuba i-vertex angle yayo nayo ibukhali, ilungile, kwaye ifunyenwe. Kukho indlela ebizwa ngokuba ithiyori yeCalabio echaza unxantathu we-isosceles njengomfanekiso obhalwe izikwere ezintathu.

## Ukubalwa kwendawo

Ukubala indawo enxantathu ye-isosceles Kuyimfuneko ukuba kuthathelwe ingqalelo oku kulandelayo: Ukuncitshiswa kufuneka kuthathelwe ingqalelo kusetyenziswa ithiyori kaPythagorean, ethi isixa sesikwere ngasinye sesiqingatha sesiseko silingana nesikwere salo naliphi na elinye lamacala amabini obude.

Ngesi sizathu, ukuba ukuphakama kufakwe endaweni, ifomula yonoxantathu be-isosceles ithathwa njengeyona iphambili kwaye isetyenziselwa ukuyifaka kolunye unxantathu, oko kukuthi, A = ibhokisi / 2.

## Ukufana kunye nokungalingani

Kwelinye icala, ii-isosceles triangles zohlukile kuba zibonakaliswa ngokuba nendawo ebizwa ngokuba yi-T kunye ne-perimeter elinganayo; Ngale ndlela i-isoperimetric iveliswa, isenza ukungalingani kwemathematika; obuyiselwe endaweni kuphela ukuba kukho unxantathu wolo hlobo kwaye ulinganayo, oko kukuthi, onke amacala ayo ayalingana.

Kukho ukulingana okwenzeka xa amacala amabini elingana kwaye enobude obulinganayo; Oko sikubiza ngokuba "a"; kananjalo elinye icala linomlinganiso "c". Ngokufanayo, ukuba amacala amabini alinganayo anobude "a" kunye nobunye ubude "c", i-bisector ye-engile yangaphakathi ilingana nenye yeefestile zayo.

## Ukuqwalasela

Lo nxantathu wahlalutywa ziingcali zezibalo ezahlukeneyo; njenge-English Ostermann kunye neWanner; i-Swiss Leonhard Euler; umphandi odumileyo ogama linguPythagoras kunye ne-Swiss Jkob Steiner, phakathi kwezinye iingcungela ezinkulu nezibalaseleyo zemathematics.

Kubalulekile ukwazi ukuba kwimathematics kukho umgca obizwa ngokuba yi-Euler; enegama lomphandi odumileyo. Lo mgca sisiphumo sohlalutyo olwenziwe sisazi sezibalo ngokwakhe, esiqwalasele oku kulandelayo: Ngumgca owela kwelinye icala lonxantathu we-isosceles; eveliswa enkosi ekudibaneni kwemigca emithathu eqala kwi-vertices yangaphakathi.

Umanyano lwezinto ekuthiwa zii-mediatrices zenziwa kumacala alo amathathu; ukwenza umanyano embindini wesazinge esibhalwe ngaphakathi konxantathu ngokwawo. Ngale ndlela, umgca ka-Euler ungqinelana nale symmetry; Kukholelwa ukuba yenziwe kuphela kolu hlobo loonxantathu, apho i-axis esembindini ihambelana nokuphakama.

Ukuba ulithandile eli nqaku kwaye ufuna ukwazi ngakumbi ngale nto kunye nezinye izihloko, siyakumema ukuba ufunde le post ilandelayo Iindidi zonxantathu: amagama, iimpawu kunye nokunye