Final answer:
To find the perimeter of a similar rectangle with a width of 12 inches, we need to find the length of the rectangle. The length can be found using the given width and perimeter values by setting up a proportion. The perimeter of the similar rectangle is then calculated using the formula 2 * (length + width).
Step-by-step explanation:
To find the perimeter of a similar rectangle with a width of 12 inches, we need to find the length of the rectangle. Since the width is 8 inches and the perimeter is 30 inches, we can set up a proportion:
8 inches / 30 inches = 12 inches / x inches
Cross-multiplying, we get 8x = 360. Dividing both sides by 8, we find that x = 45.
So, the length of the rectangle is 45 inches. The perimeter of the similar rectangle is then calculated as:
2 * (length + width) = 2 * (45 + 12) = 114 inches.