Final answer:
To find the height of the larger sign, determine the scale factor between the two signs and use the formula for the height of an equilateral triangle.
Step-by-step explanation:
To find the height of the larger sign, we need to determine the scale factor between the two signs. The perimeter of the original sign is 144 inches, and the new sign has a perimeter that is 1.25 times the original. This means the perimeter of the new sign is 144 x 1.25 = 180 inches.
Since the original sign is an equilateral triangle, each side has a length of 144/3 = 48 inches. The larger sign will have sides that are 180/3 = 60 inches in length.
Since the larger sign is also an equilateral triangle, we can use the formula h = (√3/2) x s, where h is the height and s is the length of a side. Therefore, the height of the larger sign is h = (√3/2) x 60 = 51.96 inches (rounded to two decimal places).