Answer:
11610
Explanation:
First you do the top rectangle which the area for that is 144 which is 4 times 4 times 3 times 3.
Then you do the middle rectangle which the area is 441 which is 7 times 7 times 3 times 3.
Then you do the last rectangle which the area is 11025 which is 15 times 15 times 7 times 7.
Then lastly you add all three areas which is 144+441+11025=11610. So therefore, the answer is 11610.