When you describe things it can be very useful to use shape vocabulary. Flat shapes such as square and circle are used as loanwords in a lot of languages but 3D shapes are not as common.
Describing patterns is harder than a lot of people think. Here are some examples in some of my old photographs.
First, I am wearing a plain suit, a checked shirt and a striped tie. The stripes run diagonally.
Next, the tunnel is made of a series of semicircular arches.
The windows of this building are tessellating (linking together with no gaps) triangles.
The heating elements in this picture form red zigzags.
This photo overlays a floral pattern onto a street scene.