Question 53421
width of first rectangle = x
length of first rectangle = x+6

width of the second rectangle = x+3
length of second rectangle = x+4

{{{2(x+3) + 2(x+4) = 54}}}
{{{2x + 6 + 2x + 8 = 54}}}
{{{4x = 40}}}
{{{x = 10}}}

Substituting x:

width of first rectangle = x = 10 cm
length of first rectangle = x+6 = 16 cm

width of the second rectangle = x+3 = 13 cm
length of second rectangle = x+4 = 14 cm