Final answer:
To calculate the area of the 12.5 foot by 18 foot wall, multiply the length by the height, resulting in an area of 225 square feet.
Step-by-step explanation:
To find the area of a rectangular wall, you simply multiply the length of the wall by its height. For a wall that measures 12.5 feet in length and 18 feet in height, the calculation would be as follows:
Area = length × height
Area = 12.5 feet × 18 feet
Area = 225 square feet
Therefore, the area of the concrete wall is 225 square feet.