Respuesta :
Remark
The area of the blue region = the entire area - the white region
Givens
Area of blue region = ???
Area of the white region = 6 * 9
Whole area = 13 * 15
Answer
Area of blue region = 13 * 15 - 6 * 9
Area of blue region = 195 - 54
Area of blue region = 141 <<<< Answer
SA of a rectangle: length * width
Find SA of the blue rectangle: 15 km * 13 km = 195 km
Find SA of the white rectangle: 9 km * 6 km = 54 km
Subtract white rectangle from blue rectangle: 195 - 54 = 141
Area of blue region: [tex] \boxed {141~km^2} [/tex]