Math

semi-circle on top  right with radius =  4  =  16pi/2  = 8pi  km^2

area of rectangle on left  side of  semi-circle = 8 * 5  = 40 km^2

area of small rectangle in the middle  = 2 * 3 = 6 km^2

area of rectangle at bottom = 5 * 8  = 40 km^2

Total area  = [  8pi + 40 + 6 + 40 ] km^2  =

[ 86 + 8pi] km^2 ≈  111.13 km^2