A cikin wannan ɗaba'ar, za mu yi la'akari da mahimman kaddarorin tsayin triangle isosceles, da kuma nazarin misalan warware matsalolin kan wannan batu.
lura: ana kiran triangle isosceles, idan biyu daga cikin ɓangarorinsa sun yi daidai (a gefe). Bangaren na uku ana kiransa tushe.
Halin tsayi a cikin triangle isosceles
Kadarori 1
A cikin triangle isosceles, tsaunukan biyu da aka zana zuwa tarnaƙi daidai suke.
AE = CD
Maimaita kalmomin: Idan tsayi biyu sun yi daidai a cikin triangle, to, isosceles ne.
Kadarori 2
A cikin triangle isosceles, tsayin da aka saukar zuwa tushe shine a lokaci guda bisector, tsaka-tsaki, da madaidaicin bisector.
- BD - tsayin da aka zana zuwa tushe AC;
- BD shi ne matsakaici, haka AD = DC;
- BD shine bisector, saboda haka kwana α daidai da kwana β.
- BD - perpendicular bisector zuwa gefe AC.
Kadarori 3
Idan an san bangarorin / kusurwoyi na triangle isosceles, to:
1. Tsawon tsayi hasaukar a kan tushe a, ana lissafta ta hanyar dabara:
- a - dalili;
- b - gefe.
2. Tsawon tsayi hbja gefe b, daidai:
p – wannan shi ne rabin kewayen triangle, lasafta kamar haka:
3. Ana iya samun tsayin daka zuwa gefe ta hanyar sintiri na kwana da tsayin gefe triangle:
lura: zuwa triangle isosceles, gabaɗayan kaddarorin tsayi da aka gabatar a cikin littafinmu - kuma ana amfani da su.
Misalin matsala
Aiki 1
An ba da triangle isosceles, wanda tushensa shine 15 cm, kuma gefen shine 12 cm. Nemo tsayin tsayin da aka saukar zuwa tushe.
Magani
Bari mu yi amfani da dabara ta farko da aka gabatar a ciki Kadarori 3:
Aiki 2
Nemo tsayin da aka zana zuwa gefen triangle isosceles mai tsayi 13 cm. Tushen adadi shine 10 cm.
Magani
Da farko, muna ƙididdige semiperimeta na triangle:
Yanzu yi amfani da dabarar da ta dace don nemo tsayi (wakilta a cikin Kadarori 3):
