bonjour

p(x) du triangle = tour du triangle = 5x+3x+4x = 12x

et

a(x) du triangle = 1/2 x base x haut = 1/2 * 4x * 3x = 6x

et

p(x) rectangle = 2 x (larg + long) = 2 * (3x+2) * 2 = 4(3x+2) = 12x + 8

et

a(x) rectangle = long x larg = (3x+2) * 2 = 6x + 4