Answer:
The length of the similar rectangle is 18 inches.
Explanation:
Similar figures have the same ratio of corresponding side lengths. In this example the width of the first rectangle is 4 inches, while the width of the second rectangle is 12 inches. We can compare them by setting up the fraction 4/12, which can be simplified to 1/3. So, the ratio between the similar rectangles is 1:3. If the length of the first rectangle is 6 inches, in order to find the length of the second rectangle, we would simply multiply by 3. So, 6 x 3 = 18, which is the length of the second rectangle.