floor tiles
甓 centers on a specific building material: floor tiles. It refers to the flat, hard pieces used to cover floors.
甓 combines 瓦 (tile, earthenware) with 辟, which likely contributes the sound. The character specifically denotes a tile used for flooring.
The top part 辟 looks like a complex pattern, and the bottom 瓦 is a tile. Picture a decorative floor tile with an intricate design.
For ヘキ, imagine laying floor tiles in a hexagonal pattern: hex -> ヘキ, and each tile clicks into place.