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1)  Quarter circle at the top with a radius   =  3.....area =  pi (3)^2 / 4  =  (9/4)pi

2)  A    (4 + 2) x 4  = 6 x 4  rectangle in the middle =  24

3) A 1 x 4  rectangle at the bottom

Again....add these together....answer is in km^2