Buna ! = )
Rezolvarea problemei :
P patrat = P dreptunghi
L = 48m
l=5/12 * L
l=5 /12 * 48
l=5 * 4
l=20 cm
P dreptunghi= 2 l + 2 L
2l + 2 L =2 * 20 + 2 * 48 =40 + 96=136 cm
P patrat=136 cm
P patrat = 4l=136 cm
l=136 : 4
l=34 cm
A patrat = l ^ 2=34 ^ 2 = 1156 cm ^2