Concentric shapes and edges
Nature shows us what works, it has evolved to be beautiful and efficient. It can inspire us to great things. It always puzzles me when people totally ignore this.
The radiating arms that support the concentric roof in the bottom photo are quite stable. However I cannot help wonder why circles were chosen to cover the rectangular shapes of cars.
The roof below makes more sense for the shapes it covers. However a lack of a gutter and down spout system and the rolled edges insure that rain will follow the curved edges and send it into the “protected” area. A look at the edge of a leaf will show a variety of ways to move the water off and away.