Final answer:
To find the length of the banner, which is stated to be three times the height, we multiply the given height of 5 feet by 3. The length of the banner is therefore 15 feet.
Step-by-step explanation:
The height of the banner is given to be one-third of its length. If the banner is 5 feet tall, to find the length x of the banner, we need to set up a proportion based on the information provided. Since the height (5 feet) is one-third of the length, the length x will be three times the height. Therefore, we simply multiply the height by 3 to get the length.
To calculate the length x, we use the equation x = 3 × 5 feet. Multiplying 3 by 5 feet, we find that x = 15 feet. Hence, the length of the banner is 15 feet.