Answer: 464 square units
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Explanation:
Refer to the figure below.
I've added lines in red to form a large square that is 24 by 24, so its area is 24*24 = 576 square units.
Region A is an 8 by 8 smaller square of area 8*8 = 64 square units.
Region B is a 12 by 4 rectangle of area 12*4 = 48 square units.
Subtract these areas from the 576 found earlier
(area of the largest square) - (area region A) - (area region B)
(576) - (64) - (48)
464
