Geometry is the branch of mathematics dealing with shape, size, space and position. Interestingly enough, all of these are also elements that can be used in artistic composition. From the simplest to the most complex, the geometric elements of a photo can play a multitude of roles.
Lines can lead the eye where the artist chooses, divide a picture into discrete areas or create boundaries which constrain and bind the the various elements of the compositions. Shapes can frame the subject, or like the line, compartmentalize the image. Occasionally, they may even become the main focus of the image. Oh, and as always, don't forget to choose the right angle for your shot.
Melbourne's Etihad Stadium has an almost endless selection of nooks and crannies to explore. Catch it on a cold winter day and there won't be too many people to get in the way of the architecture.
Olympus E-30, Zuiko Digital 14-60 f2.8-4.0 .