Saw three white objects in clear blue sky flying against the wind in triangular formation.I was sitting in the back yard at my Girlfriend's house at 5:15 CDST in Grand Rapids, Minnesota. We had just returned from Hibbing, Minnesota where we were shopping. We were about to relax and have a drink. I was leaning back in my chair looking up at the sky which was almost totally clear and blue, except for clouds near the horizon. Basically , it wa a totally clear sky, bright with sunlight. Windy.My girlfriend was checking on her flowers. I saw 3 white spots in the sky slightly southwest of vertical (toward Duluth). I thought they might be fighter airplanes which do pass over at times. And I thought they could be white birds. However these objects were very, very high or at least appeared to be and I could not see any definition in the shape as you might with a bird or plane. My girlfriend thought they appeared triangular.At first sight these spots were in a straight line and proceeding to the Northwest by West. I thought I might have seen a tether, but I may have simply interpreted the regular in line motion as tethered. I was thinking of baloons. But the fact was I knew that the objects did not appear as baloons or aircraft or birds. The three spots were not shiny. They were dead white. They proceeded in a straight line as though on the wind. I think the wind was in the opposite direction. Very soon after first sight the objects moved in relation to each other, first appearing in the shape of an "L" with two fairly close together, almost touching. But as the movement went on the three objects took positions at the vertices of a perfect equalateral triangle. The triangle did not rotate. There was no sound. The motion was very steady as you see in a flight of birds. As the white spots moved more to the Northwest, they stopped. Abruptly. The motion seemed kind of chaotic at that point, but reorginized and then began moving more or less straight south. It was then that the spots disappeared. On first sight, with the objects in line, the appearance was quite different, but I would say the distance between the two outer objects or spots and the center was about the same as the distance between the points of the triangel shape later assumed. If the points were tied together, the changing shape might have been that of triangle being rotated so that I just saw it from a different angle. In the middle of this incident I got a cell phone call from my daughter about band practice. That distracted me as I tried to get her to go and look.I called the Duluth Air National Guard security service at 5:45, a half hour after the sighting because maybe they had it on radar. Of course, I didn't get any information and really, I was happy just to report what I saw.I am certain that the thing I saw was white. Dead white. Not shiny. It didn't change direction quickly although it may have been going very fast. It must have disappeared instantly. I don't know how high it was. Certainly higher than birds flying. And. . . I have never seen any thing like it and I have never made a report before. I am 67 years old.