Answer:
91 sq. feet.
Step-by-step explanation:
The flag has length 15 ft and width 7 ft. and the blue rectangle has a length of 7 ft and a width of 3 ft.
Now, 13 alternating red and white stripes of 1 ft width are there in the flag.
Therefore, there will be a total of 7 red strips of which 2 with width 1 feet and length (15 - 7) = 8 feet length. and 5 with width 1 feet and length 15 feet.
So, the total area of the flag which is only red will be (1 × 8) × 2 + (1 × 15) × 5 = 16 + 75 = 91 square feet. (Answer)