The factory is 112 miles North of the warehouse. North and South is the Y axis.
The warehouse is located at Y -56, add 112 to that and Y = positive 56, so the factory is located at Y = 56.
Using the distance formula we can find the distance between the warehouse and the airport:
Distance = SQRT( (x2-x1)^2 + (Y2-y1)^2)
Ware house X = 42, Y = -56
Airport X = -42, Y = 56
Distance = SQRT (( -42 - 42)^2 + (56 - -56)^2) = 140 miles
The factory is on X 42, Y 56, which is the same Y value as the airport, so the distance between the airport and the factory is the change in X
-42 to 0 = 42 and 0 to 42 = 42, 42+ 42 = 84 miles.
Total distance = 140 + 84 = 224 miles.