Răspuns :
P =2 L + 2 l
L -7.4 = l
L = l +7.4
248.4 =2 (l +7.4 )+2 l
248.4 =2 l +14.8 +2 l
4 l =248.4 -14.8
4 l =233.6
l =58.4
L =l +7.4
L = 58.4 +7.4
L =65.8
L -7.4 = l
L = l +7.4
248.4 =2 (l +7.4 )+2 l
248.4 =2 l +14.8 +2 l
4 l =248.4 -14.8
4 l =233.6
l =58.4
L =l +7.4
L = 58.4 +7.4
L =65.8