Answer:
130.5 mi sq
Triangle: A = bh/2
A = ((21 - 12) x (3))/2
A = (9 x 3)/2 = 13.5 mi sq
Middle rectangle: A = bh
A = (6 + 3)(15 - 3)
A = (9)(12) = 108 mi sq
Last rectangle: A = bh
A = 3 x 3 = 9 mi sq
TOTAL: 13.5 + 108 + 9 = 130.5 miles sq
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