Okuqukethwe
Kule ncwadi, sizocubungula izici eziyinhloko zokuphakama kukanxantathu we-isosceles, futhi sihlaziye izibonelo zokuxazulula izinkinga kulesi sihloko.
Qaphela: unxantathu ubizwa amasosles, uma izinhlangothi zayo ezimbili zilingana (lateral). Uhlangothi lwesithathu lubizwa ngokuthi isisekelo.
Izakhiwo ze-altitude kunxantathu we-isosceles
Impahla 1
Kunxantathu we-isosceles, ukuphakama okubili okudwetshelwe emaceleni kuyalingana.
AE = CD
Hlehlisa amagama: Uma ama-altitudes amabili elingana kunxantathu, kusho ukuthi i-isosceles.
Impahla 2
Kunxantathu we-isosceles, ukuphakama okwehliselwe esisekelweni ngesikhathi esifanayo kuyi-bisector, i-median, kanye ne-perpendicular bisector.
- BD – ubude budonseleka esisekelweni AC;
- BD ungumphakathi, kanjalo AD = DC;
- BD i-engeli, ngakho-ke i-engeli α ilingana ne-engeli β.
- BD – i-perpendicular bisector eceleni AC.
Impahla 3
Uma izinhlangothi/ama-engeli kanxantathu we-isosceles aziwa, khona-ke:
1. Ubude bobude hakwehliswe esisekelweni a, ibalwa ngefomula:
- a - isizathu;
- b – side.
2. Ubude bobude hbedonseleka eceleni b, kuyalingana:
p – lena uhhafu-perimitha kanxantathu, ibalwa kanje:
3. Ukuphakama ohlangothini kungatholakala nge-sine ye-engeli nobude bohlangothi unxantathu:
Qaphela: kunxantathu we-isosceles, izici zobude ezijwayelekile ezethulwe eshicilelweni lethu - nazo ziyasebenza.
Isibonelo senkinga
Umsebenzi 1
Unxantathu we-isosceles unikezwa, isisekelo sawo esingu-15 cm, kanti uhlangothi luyi-12 cm. Thola ubude bobude behliselwe esisekelweni.
Isixazululo
Masisebenzise ifomula yokuqala ethulwe kuyo Impahla 3:
Umsebenzi 2
Thola ubude obudwetshelwe ohlangothini lukanxantathu we-isosceles ubude obungu-13 cm. Isisekelo somfanekiso singama-cm angu-10.
Isixazululo
Okokuqala, sibala i-semiperimeter kanxantathu:
Manje sebenzisa ifomula efanelekile yokuthola ubude (okumelelwe ku- Impahla 3):
