An example of a geometric shape among the listed options is "Cloud." While clouds are not a perfect geometric shape, they can represent shapes in geometric discussions. However, if you are looking for a straightforward geometric shape, consider common geometric terms like circle, square, triangle, etc., which aren't directly listed here.
If you're specifically looking for an answer within the options Chalkboard, Cloud, Dirt, and Lemonade, the best choice would be Cloud, as it can be associated with different shapes in mathematical contexts. However, none of the options represents a traditional geometric shape like a square or triangle.
Could you clarify or provide more context regarding the question?