Question

Помогите решить, пожалуйста.

Answer 1

P =AB+BC+AC = 1.6AC + 1.6AC + AC = 4.2AC
4.2AC = 21
AC = 5
AB = BC = 5*1.6 = 8

A=C => AB = BC
P = AB+BC+AC = 0.8AC+0.8AC+AC = 2.6AC
2.6AC = 7.8
AC = 3
AB = BC = 0.8AC = 2.4