Final answer:
The length of side "c" in a square is unrelated to the areas given for the green and red squares; however, if "c" were to be the sum of one side of each square, the combined length would be 7 feet. The area represented by c² would be 49 square feet. The provided answer choices in the question do not match this calculation, suggesting an error in the question.
Step-by-step explanation:
The question asks us to find the length of side "c" in a square. Given that the area of the green square is 9 square feet and the area of the red square is 16 square feet, we know that the length of each side of a square is the square root of the area. Therefore, the length of the green square's side is the square root of 9, which is 3 feet, and the length of the red square's side is the square root of 16, which is 4 feet.
The length of side "c" is not directly related to these individual squares. However, the area of a square is equal to the side length squared, so c² represents the area of a square with side length c. If c is to be the combined length of one side of the green square plus one side of the red square, then c would be 3 feet + 4 feet = 7 feet. Therefore, the area represented by c² is 49 square feet, and side "c" itself would be of length 7 feet.
Since the answer choices do not include 7 feet or 49 square feet, it appears there may be an error in the question as none of the answer choices (A) 5 ft, (B) 25 ft, (C) 81 ft, (D) 128 ft correspond to the calculated length side "c".