a) Δ ABC= triunghi echilateral
Perimetrul ΔABC=AB+AC+BC=3x9,7=29,1 cm
b) PΔABC=AB+AC+BC=16cm+(16:2)cm+10,6 cm=34,6 cm
c) P ΔABC=12 cm+12/0,8=12cm+15cm=27 cm
AB=0,8(AC+BC)=12⇒AC+BC=12:8/10=12x10/8=15 cm suma laturilor AC+BC
d) AB+AC+AB+BC+AC+BC=15cm+16cm+17cm=48 cm
2x(AB+AC+BC)=48 cm
AB+AC+BC=48 cm:2
AB+AC+BC=24 cm ↔ perimetrul Δ ABC
