Answer:
18 in
Explanation:
Area of rectangle = 3 times the area of the square
Area of square = a² ; a = side length
a = 12 in
Area of square = 12² = 144 in²
Area of rectangle = 3 * 144 = 432 in²
Length of rectangle = 24 in
Width = x
Area of rectangle = length * width
432 = 24 * x
x = 432 / 24
x = 18 in