Răspuns :
A=70
(x, y) d.p. (5, 7)
x=5k
y=7k
A=(C₁·C₂):2
70=(5k·7k):2
140=35k²
k²=4
k=2
x=10 cm
y=14 cm
(x, y) d.p. (5, 7)
x=5k
y=7k
A=(C₁·C₂):2
70=(5k·7k):2
140=35k²
k²=4
k=2
x=10 cm
y=14 cm