a+b+c=65, a=b:3⇒b=3a
c=3b=3×3a=9a
a+3a+9a=65
13a=65
a=65/13
b=3a=(3×65)/13=195/13
c=9a=(9×65)/13=585/13
a=65/13, b=195/13, c=585/13
2) perimetrul =a+a+b+b=2(a+b)
2(a+b)=76 cm
a+b=38
a=b-10
(b-10+b)=38
2b=38+10
2b=48
b=24 cm , a=b-10=24-10=14 cm
a=14, b=24,
aria= a×b=14×24=336 cm²