Răspuns :
AB=60
BC=CA
P=AB+BC+CA=240
60+CA+CA=240
2xCA=240-60
2xCA=180
CA=180:2
CA=90 => CB=90
BC=CA
P=AB+BC+CA=240
60+CA+CA=240
2xCA=240-60
2xCA=180
CA=180:2
CA=90 => CB=90
notam cu a, b, c lungimile laturilor, a=60, b=c, P=a+b+c=240
60+b+b=240
2b=180, b=90, c=90
60+b+b=240
2b=180, b=90, c=90