There’s a lot of power in the humble triangle. Just as it brings strength to all kinds of mechanical structures, the triangle makes your photographs stronger, too.
One way to use a triangle is to place one side at the bottom of your frame. That will anchor your subject, placing it on a firm foundation. This works whether it’s a portrait or a landscape. Orienting the triangle this way makes your composition feel very stable and solid. Whatever is at the top of the triangle will be perceived as superior, which can be very important when you’re posing a group of people.
If you turn the triangle upside down, with a point at the bottom of the frame, whatever is at that point will come across as less important. This feeling of height equating to strength is deeply engrained in our psyche.
Sometimes you’ll have very clear lines forming the triangle, but more often one or more legs will be vague, forming an implied shape.
Converging lines are another form of triangle, conveying the sense of distance in a two-dimensional photograph. The lines don’t have to be entirely within the frame, as they are in this garden image. Our brains are very good at completing familiar figures.
When the triangle is tipped on its side, forming an unstable figure, it brings a strong dynamic to your composition. Try a composition with a right triangle turned so it is off balance and would tumble if it were a three-dimensional object.
Your photograph does not need to be limited to a single triangle. In this photograph of iris blossoms there are two prominent triangles, but you can have many more. This is a good way to find patterns and reduce complexity in busy subjects.
Whether you’re photographing one person or a group, an intimate detail, or the sweep of the landscape on your vacation, seek out triangles in your composition as you frame your shot. They’re not the only composition tool in your arsenal, but they’re one of the most powerful.