Which of the following is a universally adopted shape of cell?

Squares, circles, and triangles are also common shapes of cells, but they are not as efficient as hexagons. Squares and circles have more wasted space than hexagons, and triangles are not as stable.

Here is a diagram of a honeycomb pattern of hexagonal cells:

As you can see, the cells are arranged in a way that maximizes the surface area of each cell. This is important for cells because it allows them to exchange nutrients and waste products with each other.

I hope this explanation was helpful!