Since coordinates can't exceed 180 degrees I'm willing to assume step 4 should actually be the coordinates - So I just overlaid a 180 degree protractor over the existing map to get the coords.
http://i.imgur.com/ntWUy0k.png
But then I thought maybe it isn't the radius after all, maybe that is designating the point of reference for the coordinates? So I rotated it.
http://i.imgur.com/MFyuqXo.png
So you can see we have many coords to check out.
Step 1) Align the protractor on the 140/138 degree line
Step 2) Rotate the protractor 90 degrees So also I was thinking Step 1 should be to rotate the protractor 90 degrees
Step 3) The coordinates are on this side of the globe.
Step 4) Draw Lines - These are the coordinates