All of these factors would be important when creating a toy. I would measure to make sure that all the components of the toy fit with one another. I would also use the idea of dimensions to determine whether the dimensions of the toy are appropriate for the intended users (for example, is there a risk of swallowing?). I would use the idea of volume to explore the materials I am using and whether these might be too light or too heavy according to the size. Finally, I would use the surface area to ensure that the toy would not collect a lot of dust.