Okuqukethwe
Kulolu shicilelo, sizocubungula incazelo, ukuhlukaniswa kanye nezakhiwo zomumo wejometri oyinhloko - unxantathu. Sizophinde sihlaziye izibonelo zokuxazulula izinkinga ukuze sihlanganise indaba ethulwayo.
Incazelo kanxantathu
triangle - Lesi sibalo sejometri endizeni, ehlanganisa izinhlangothi ezintathu, ezakhiwe ngokuxhuma amaphuzu amathathu angalali emgqeni owodwa oqondile. Uphawu olukhethekile lusetshenziselwa ukuqokwa - △.
- Amaphuzu A, B kanye no-C ayizingqimba zikanxantathu.
- Izigaba AB, BC kanye ne-AC ziyizinhlangothi zikanxantathu, ezivame ukuchazwa njengohlamvu olulodwa lwesiLatini. Isibonelo, AB= a, BC = b, KANYE = c.
- Ingaphakathi likanxantathu liyingxenye yendiza eboshwe izinhlangothi zikanxantathu.
Izinhlangothi zikanxantathu kuma-vertices zakha ama-engeli amathathu, ngokwesiko achazwa ngezinhlamvu zesiGreki – α, β, γ njll. Ngenxa yalokhu, unxantathu ubizwa nangokuthi ipholigoni enamakhona amathathu.
Ama-engeli angabuye achazwe kusetshenziswa uphawu olukhethekile “∠"
- α – ∠BAC noma ∠CAB
- β – ∠ABC noma ∠CBA
- γ – ∠ACB noma ∠BCA
Ukuhlukaniswa kukanxantathu
Ngokuya ngosayizi wama-engeli noma inombolo yezinhlangothi ezilinganayo, izinhlobo ezilandelayo zezibalo ziyahlukaniswa:
1. i-acute-angled – unxantathu onawo womathathu ama-engeli ashubile, okungukuthi ngaphansi kuka-90°.
2. vuma Unxantathu lapho enye yama-engeli inkulu kuno-90°. Amanye ama-engeli amabili ashubile.
3. wamaqhuqhuva – unxantathu lapho enye yama-engeli ilungile, okungukuthi ilingana no-90°. Emfanekisweni onjalo, izinhlangothi ezimbili ezakha i-engeli elungile zibizwa ngokuthi imilenze (AB no-AC). Uhlangothi lwesithathu oluphambene ne-engeli elungile yi-hypotenuse (BC).
4. Ulamula Unxantathu lapho zonke izinhlangothi ezinobude obuhlukene.
5. I-Isosceles – unxantathu onezinhlangothi ezimbili ezilinganayo, ezibizwa nge-lateral (AB kanye no-BC). Uhlangothi lwesithathu luyisisekelo (AC). Kulo mfanekiso, ama-engeli ayisisekelo ayalingana (∠BAC = ∠BCA).
6. I-Equilateral (noma ilungile) Unxantathu lapho zonke izinhlangothi zinobude obufanayo. Futhi wonke ama-engeli ayo angu-60°.
Izakhiwo zikanxantathu
1. Noma yiziphi izinhlangothi zikanxantathu zincane kunezinye ezimbili, kodwa zikhulu kunomehluko wazo. Ukuze kube lula, siyakwamukela ukuqokwa okujwayelekile kwezinhlangothi - a, b и с… Bese:
b – c <a <b + cAt b > c
Lesi sakhiwo sisetshenziselwa ukuhlola amasegimenti omugqa ukubona ukuthi angakwazi yini ukwakha unxantathu.
2. Isamba sama-engeli anoma yimuphi unxantathu ngu-180°. Kulandela kusuka kulesi sakhiwo ukuthi kunxantathu we-obtuse ama-engeli amabili ahlala ebukhali.
3. Kunoma yimuphi unxantathu, kune-engeli enkulu ebhekene nohlangothi olukhulu, futhi ngokuphambene.
Izibonelo zemisebenzi
Umsebenzi 1
Kunama-engeli amabili aziwayo kunxantathu, 32° kanye no-56°. Thola inani le-engeli yesithathu.
Isixazululo
Ake sithathe ama-engeli aziwayo ngokuthi α (32°) kanye β (56°), kanti okungaziwa - ngemuva γ.
Ngokusho kwendawo mayelana nesamba sawo wonke ama-engeli, a+b+c = 180 °.
Ngenxa yalokho, i- γ = 180° -a-b = 180 ° - 32 ° - 56 ° = 92 °.
Umsebenzi 2
Kunikezwe amasegimenti amathathu obude obu-4, 8 kanye no-11. Thola ukuthi angakwazi yini ukwakha unxantathu.
Isixazululo
Masibhale ukungalingani kwesegimenti ngayinye yalezi zinikeziwe, ngokusekelwe kule ndawo okukhulunywe ngayo ngenhla:
11 – 4 <8 <11 + 4
8 – 4 <11 <8 + 4
11 – 8 <4 <11 + 8
Zonke zilungile, ngakho-ke, lezi zingxenye zingaba izinhlangothi zikanxantathu.