latimea /-----/
} Suma = Semiperimetrul = > 86 : 2 = 43
lungimea /-----/+8
43 - 8 = 35 am egalat partile
35 : 2 = 17,5 m o parte egala
latimea = 17,5
lungimea = 17,5 + 8 = 25,5
P = ( 17,5 + 25,5) x 2 = 43 x 2 = 86 m
II varianta
latimea= x
lungimea = x + 8
(x + x +8) x 2 = 86
2x + 8 = 86 : 2
2x + 8 = 43
2x= 43 - 8
2x = 35
x = 35 : 2
x = 17,5
latimea = 17,5
lungimea = 17,5 + 8 = 25,5