Bonsoir

aire du carré : 30 x 30 = 900 m^2

900 m^2 => 75600 €

1 m^2 => 75600 / 900 = 84 €

aire du rectangle : 30 x 50 = 1500 m^2

1 m^2 => 84 €

1500 m^2 => ? €

= 1500 x 84

= 126 000 €