Demak, har qanday aylana uchun yuzani topish formulasi:
S = πr2
Bizga hozir radius kerak. Teng yonli uchburchakka tashqi chizilgan aylana radiusi quyidagi formula bo'yicha topiladi:
R = a / √3 yoki 
Demak, agar aytaylik uchburchak tomonlari 12sm deb olinadigan bo'lsa, unda aylananing yuzasi:
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