Answer:
Length = 9 in
Width = 12 in
Step-by-step explanation:
Length L = 3 + W
Perimeter P = 42 in
Perimeter = 2L + 2W
plugin values:
42 = 2(3 + W) + 2W
42 = 6 + 2W + 2W
42-6 = 4W
W = 36 / 4
W = 9
solve L by substituting the value of W=9 into the equation:
L = 3 + W
L = 3 + 9
L = 12
therefore, the dimensions of the rectangle:
Length = 9 in
Width = 12 in
