a+b+c=77
b=2a
c=b+2
c=2a+2
a+2a+2a+2=77 (scazi 2)
5a=75 (imparti la 5)
a=75/5
a=15
b=2a
b=15 ori 2
b=30
c=b+2
c=30+2
c=32
sau
l---l = a
l---l---l = b
l---l---l+2 = c
a+b+c=77
1 segment + 2 segmente + 2 segmente + 2 = 77
5 segmente + 2 = 77
5 segmente = 75
1 segment = 75/5
1 segment = 15 = a
b = 2 segmente = 15 ori 2 = 30
c = 2 segmente + 2 = 15 ori 2 + 2 = 30 + 2 = 32