Over the distance of the US this will be negligible enough for basic approximation (it will certainly be within an order of magnitude). If it’s a high school assignment it is also totally reasonable to simplify the problem to plane geometry (even if inaccurate) for the sake of leaning the concept.
Am I dumb or is there nothing wrong with the map
I think it’s more about how the lines crisscross the map than anything else.
cities are off, like denver is on the other side of colorado
Spherical trig is required to calculate these distance, not plane trigonometry. Because the earth is (mostly) a sphere.
Over the distance of the US this will be negligible enough for basic approximation (it will certainly be within an order of magnitude). If it’s a high school assignment it is also totally reasonable to simplify the problem to plane geometry (even if inaccurate) for the sake of leaning the concept.