Răspuns :
A= L x l (A= arie , L = lungime , l= latime)
P=2L+2l
54=2x17 + 2 x l
54=34+ 2 x l
54-34=2 x l
20 = 2 x l => l =20:2 => l=10
A =17 x 10 = 170
P=2L+2l
54=2x17 + 2 x l
54=34+ 2 x l
54-34=2 x l
20 = 2 x l => l =20:2 => l=10
A =17 x 10 = 170