Unxantathu Obtuse: ubude macala, udibaniso engile. Ochazwa unxantathu obtuse

Nkqu nabantwana uthole uyazi ukuba ikhangeleka ngathi unxantathu. Kodwa kunjalo, yintoni na ukuba abadlali bethu sele Ndiyaqala ndiyakuqonda esikolweni. Olunye uhlobo yi unxantathu obtuse. Qonda ukuba yintoni na kulula ukubona ukuba umfanekiso kunye nomfanekiso wakhe. Ngethiyori, oku ukuze ngokuba "yepholigoni elula" kunye macala emithathu eziphezulu, enye yazo i engile obtuse.

Siyazi baqonde iingqiqo

Wew bahlule ezi ntlobo imilo enamacala amathathu: oonxantathu etsolo-engile egqithe, ekunene-angled kunye obtuse-engile egqithe. Iimpawu zezi yeepoligoni ezilula minye wonke. Ngoko, kuba zonke ezi ntlobo ziya bayiqaphela le nokungalingani. Umdibaniso ubude naziphi macala mabini ngokuqinisekileyo ibe ngaphezu kokuba ukwandiswa yomntu wesithathu.

Kodwa ukuze siqiniseke ukuba sithetha umzobo epheleleyo, kunokuba iseti encopho ngamnye, kufuneka ukhangele ukuba athobele kwiimfuno ezisisiseko ukuba isibalo engile obtuse kanxantathu ilingana ^180. Oku kuyinyaniso ukuba ezinye iindidi ze amanani kunye macala ezintathu. Noko ke, kukho unxantathu obtuse, enye ikona uya kuba nangakumbi ^90, yaye kunyanzeleka ukuba babini baseleyo babe elibukhali. Kulo mzekelo, iya kuba ekujikeni inkulu malunga kwicala elide. Noko ke, le nto zonke iimpawu unxantathu obtuse-engile egqithe. Ke kaloku, esazi nje ezi mpawu, abafundi bakwazi ukucombulula iingxaki ezininzi geometry.

Kuba polygon ngalinye eziphezulu ezintathu kuyinyaniso kananjalo ukuba, lo gama kuthathelwa ngapha nangapha, sifumana ekujikeni, ubukhulu apho iya kulingana isixa eziphezulu non-omelene langaphakathi amabini kunye naye. Umhlaba ojikeleze unxantathu obtuse zibalwa ngendlela enye nezinye amanani. Nguye udibaniso ubude onke macala ayo. Ukuze ubone indawo lo nxantathu zemathematika iifomyula ezahlukeneyo zathathwa, ngokuxhomekeke idatha kuyo ekuqaleni ngoku.

manqaku achanekileyo

Enye into ebalulekileyo ekucombululeni iingxaki we geometry unendima echanekileyo. Amaxesha amaninzi Utitshala izibalo bathi kuya kunceda kuphela ukwenz anikwe yaye yintoni uya kubizwa kuwe; kodwa 80% kufutshane impendulo echanekileyo. Kubalulekile ke ngoko ukuba akwazi ukwakha njani unxantathu obtuse. Ukuba ufuna nje umzobo ezingenzeka, unako ukuzoba nayiphi yepholigoni enamacala amathathu ukuze enye ikona nto ixesha ^elide-90.

Ukuba amaxabiso anikwe ezithile ubude icala okanye izidanga-engile, ukusondela kufuneka triangle obtuse ngokungqinelana kunye nabo. Kuyimfuneko ukuzama ezibonisa ngokuchanileyo engile ubuninzi, ukubala usebenzisa i neprotrektha, bekunye kulingana data ngokwemiqathango kwicala ukubonisa.

main line

Amaxesha amaninzi, besikolo abazi ungathanda nje ngayo abo okanye ezinye amanani. Ukuze athintele kuphela inkcazelo malunga unxantathu indlela obtuse kunye uxande. Mathematics ke ukuba ulwazi lwabo iimpawu ezingundoqo amanani kufuneka epheleleyo ngakumbi.

Ngenxa yoko, umfundi ngamnye kufuneka abe inkcazelo ecacileyo bisector, median, ukuphakama nkqo. Ukongeza, kufuneka azi iipropati zabo ezisisiseko.

Ngoko ke, lo bisector engile yahlulwe kubini, kwaye icala - ibe ziqwempu ukuba ngokomlinganiselo emacaleni ezikufutshane.

Udibaniso wahlula unxantathu nganye kwimimandla emibini iyalingana. Kwindawo apho phambana, ngalinye leyo ingxolo ibe ubude ezimbini ratio 2: 1, xa zijongwe ukusuka phezulu, ukusuka apho kwathi. A udibaniso enkulu eyazisa kwicala awo.

Akukho ingqalelo encinane into ihlawulwe indawo. Kuyinto aa Incopho na icala ekujikeni. Ukuphakama nxantathu obtuse uneempawu zawo. Ukuba wenziwa ukusuka kwincam elibukhali, oko angawi kwicala buyimilo elula, kunye nokuqhubekeka yayo.

Le nkqo - icandelo ukuthi isuka kumbindi ngohlangothi nxantathu. Ngelo xesha nye emi kuyo kwindawo esinekona sasekunene.

Ukusebenza ngezangqa

Ekuqaleni isifundo geometry we abantwana ngokwaneleyo ukuba baqonde ukuba sisondele njani unxantathu obtuse, bafunde ukwahlula oko kwezinye iintlobo, kwaye khumbula iimpawu zalo ezisisiseko. Kodwa abafundi bezikolo eziphakamileyo ukuba ulwazi akwanelanga. Umzekelo, kwi uviwo Imibuzo ebuzwa rhoqo malunga nezisekelwe baza babhala. Okokuqala kubhekiselele eziphezulu ezintathu unxantathu, kwaye enye kwincopho eqhelekileyo kunye onke amaqela.

Ukwakha unxantathu obtuse sibhalwe okanye nezisekelwe kunzima kakhulu, ngenxa yokuba kufuneka uqale ukufumana phandle apho ufuna embindini wesangqa kunye radius yayo. Hi ndlela leyi, iya kuba sisixhobo ebalulekileyo kule meko ipensile kuphela nomlawuli, kodwa ikhampasi.

kuphakama ubunzima efanayo xa kusakhiwa iimilo sibhalwe macala ezintathu. Zezibalo zathathwa ifomula ezahlukeneyo kusenza sikwazi ukubona indawo yabo ngokuchanekileyo kangangoko kunokwenzeka.

oonxantathu, sibhalwe

Njengoko kuchaziwe ngaphambili, ukuba isangqa udlula zonke zontathu eziphezulu, ngoko ke kuthiwa kwisangqa nezisekelwe. osemqoka yalo esentloko kukuba yahlukile. Ukuze ufumanise ukuba ibekwe njani nezisekelwe isangqa unxantathu obtuse, umele ukhumbule ukuba iziko yayo imi kuhlangana midperpendiculars emithathu ukuya emacaleni mzobo. Ukuba polygon yondele-engile egqithe kunye eziphezulu ezintathu, le ngongoma ziya kuba ngaphakathi kwakhe, ngendlela obtuse - phesheya.

Ukwazi, Ngokomzekelo, ukuba omnye emacaleni unxantathu obtuse-engile egqithe ilingana radius yayo, unako ukufumana angle edulusele malunga ubuso dumeke. sine balo babulingana umphumo ngokwahlula ubude icala ezaziwayo-kakuhle 2R (apho R - na embindini wesangqa). Oko ke isono engile uyalingana ½. Ngenxa yoko, i-engile ilingana ^150.

Ukuba ufuna ukufumana embindini wesangqa unxantathu obtuse, ngoko ulwazi luncedo malunga ubude macala (c, v, b) kunye kwindawo yayo S. Ngenxa kwirediyasi ibalwa ngale ndlela ilandelayo: (c x v x b): 4 x S. Ngendlela, kwaye ayinamsebenzi yintoni na uhlobo wena mzobo: unxantathu ubhetyebhetye obtuse, i isosceles, yayiyazi-angled ngqo-okanye. Kuyo nayiphi na imeko, Bulelani wokubala, ungafunda indawo kunikwa buyimilo onamacala amathathu.

unxantathu

Kwakhona yinto exhaphakileyo ukusebenza kunye izangqa sibhalwe. Ngokutsho komnye iifomyula, kwirediyasi isafobe enjalo, ½ liphindaphindwe iperimitha iya kulingana kummandla kanxantathu. Noko ke, ngokuba ikufumanisileyo kufuneka wazi inxalenye unxantathu obtuse-engile egqithe. Ngapha koko, ukuze kuqinisekiswe ukuba umjikelezo ½, kuyimfuneko ukuba babeke phantsi ubude bazo yahlulwe 2 kwaye.

Ukuze uqonde apho ufuna embindini wesangqa abhaliwe unxantathu obtuse, kuyimfuneko ukuchitha bisector ezintathu. Le line, leyo kokwaba iimbombo kwisiqingatha. It is at ekudibaneni kwaye iya kuba embindini wesangqa. Kulo mzekelo, iya kuba equidistant ngalinye amaqela.

Kwirediyasi kwisangqa ebhaliwe unxantathu obtuse-engile egqithe lilingana ingcambu ye zabucala (pc) x (PV) x (PB): p. Kulo mzekelo, p - yinto nesiqingatha-umjikelezo unxantathu, c, v, b - ecaleni kwayo.