The Summer Triangle is a quasiconstellation consisting of the three brightest stars of three prominent constellations. The term "summer triangle" only applies to the Northern Hemisphere. While the parts of the triangle may be visible from parts of the Southern Hemisphere, they are not nearly as prominent or as high in the sky there. The Summer Triangle, as its name implies, is also most visible in summer, but can also be seen in spring and fall.
Any three points form a triangle, but these three stars form a pretty obvious right triangle. The three stars are:
These three stars will be the first stars to become visible after sunset, and should be visible even in areas with light pollution. The triangle defined by these three stars is full of various celestial objects, and can also be used as a guide towards other, less noticeable constellations.