Three points of light, flying formation, demonstrating control of inertia and momentum.I was on the roof of our home (most houses in Athens at that time had flat roofs)with my Dad observing the stars with a small telescope. My Dad noticed what appeared to be a spacecraft in low orbit, illuminated by the sun which had just set. I saw it, then we both saw a second spacecraft (both pinpoints of light) "below" it, or in formation, abeam it and maybe 100 miles <?>to the side of the other. We watched these for a few minutes, tracking our heads in the direction of travel, when we noticed with our peripheral vison a third light approaching from the opposite, and slightly below, other direction. They abruptly stopped when they met to form a perfect equilateral triangle. Then they paused, and moved off in a third direction. A short time later a family friend screeched to halt in front of our house, asked if we saw it and repeated our observation adding that he had had a yard full of people who also saw it.