47cm=470mm, noi o sa lucram in milimetri . Notam segmentele cu a,b si c
a supra 12= b supra 15 =c supra 20 = k noi stim ca a+b+c=470mm
a supra 12=k => a=12k
b supra 15=k=> b=15k
c supra 20=k=> c=20k
12k+15k+20k=470 <=> 47k=470 <=> k=10mm
a=12k => a= 12 ori 10 =>a=120mm=12cm
b=15k=> b=15 ori 10=> b=150mm=15cm
c=20k=> c=20 ori 10=> c=200mm=20cm
