In this series the landscape shaped pieces are using the golden ratio. I won’t go into all details about this here but essentially the ratio between the long and the short side is 1.61803. To be precise, this should be (1+√5)/2.
These pieces are based on the 16x9 proportion in landscape format. With this proportion the relationship between the length and height is not one half, so, in my construction of the geometry, I have added a single unit height rectangle at the bottom of each composition in an appropriate colour. This provides the ability to use vertical symmetry.
I make use of the symmetry in all directions but then, sometimes deliberately offset some components. I am using polygons and circles and often triangles are filled with colour or appropriate images that work well together. The colours are usually picked out from the photographs, but then - not always!