Okuqukethwe
Kule ncwadi, sizocabangela indlela yokubala umjikelezo kanxantathu futhi sihlaziye izibonelo zokuxazulula izinkinga.
I-Perimeter Formula
Ipherimitha (P) yanoma yimuphi unxantathu ilingana nesamba sobude bazo zonke izinhlangothi zayo.
P = a + b + c
Ipherimitha kanxantathu we-isosceles
Unxantathu we-isosceles ungunxantathu onezinhlangothi ezimbili ezilinganayo (asiwathathe njenge b). Side a, enobude obuhlukile kunamaceleni, isisekelo. Ngakho, i-perimeter ingabalwa ngale ndlela elandelayo:
P = a + 2b
Ipherimitha kanxantathu olinganayo
Unxantathu olinganayo noma ongakwesokudla ubizwa ngokuthi, lapho zonke izinhlangothi zilingana (asithathe njenge a). I-perimeter yesibalo esinjalo ibalwa ngale ndlela elandelayo:
P = 3a
Izibonelo zemisebenzi
Umsebenzi 1
Thola i-perimeter kanxantathu uma izinhlangothi zayo zilingana: 3, 4 no-5 cm.
Isinqumo:
Sifaka esikhundleni samanani aziwa yimibandela yenkinga bese sithola:
P=3cm+4cm+5cm=12cm.
Umsebenzi 2
Thola i-perimeter kanxantathu we-isosceles uma isisekelo sayo singu-10 cm futhi uhlangothi lwayo luyi-8 cm.
Isinqumo:
Njengoba sazi, izinhlangothi zikanxantathu we-isosceles ziyalingana, ngakho-ke:
P = 10 cm + 2 ⋅ 8 cm = 26 cm.