As there is no flat earth map I thought I'd have a go at making one

I had a look on Google Maps and used that as my source for distances between places.

Obviously if you don't accept those distances as accurate then that's going to be a problem from the start but given that Google Maps is used by millions of people to get around you'd think we'd know about it if their maps were wrong.

I took some US Cities - I used mainland US partly because it's continental so we get away from complexities about measuring distances across oceans. I picked them fairly arbitrarily but I wanted them far apart as this is where we should see most difference between a flat earth and a globe.

I started with Seattle. Final image is at the bottom of this post.

The distance between Seattle to New York is 2405 Miles

So I drew a black circle diameter 2405 pixels. Seattle is the centre. New York must be somewhere on that circle.

New York to Dallas is 1368 miles. I picked an arbitrary point on the circle surrounding Seattle - to the right of the circle as New York is due East of Seattle. I called that point New York and drew a red circle 1368 pixels around that point.

So Dallas must be somewhere on that red circle.

Seattle to Dallas is 1684 miles so I drew another blue circle around Seattle of diameter 1684 pixels. Dallas must be somewhere on that blue circle

So, Dallas must be on the intersection between the red and blue circles.

There are 2 possibilities as the circles intersect in 2 places. Dallas is south of both New York and Seattle though so I've picked the lower one and called that Dallas.

So now we know where Seattle, New York and Dallas are in relation to one another.

I've marked the cities with rough X's and labelled them.

Now what happens if we add a 4th city?

I picked Minneapolis as it is fairly central to the above 3 cities.

The distance from Minneapolis to

New York is 1020 miles

Seattle is 1384 miles

Dallas is 1389 miles.

So I've drawn green circles with the corresponding number of pixels around those 3 cities.

Minneapolis must be somewhere on each of those green circles so it must be at the intersection of them.

The problem is the three green circles don't all intersect at any point. So either:

1) The distances on Google Maps are wrong

2) I have made an error somewhere in my reasoning or method

3) The earth isn't flat.

Are there any other possibilities?