What are non examples of the hemisphere?

Non-examples of a hemisphere would include a cube, a pyramid, or a cylinder, as these shapes do not have a curved surface that could be divided into two equal parts. In geography, a non-example of a hemisphere would be a country or a city, as they are not spherical in shape. In mathematics, a non-example of a hemisphere would be a line segment or a polygon, as they do not represent a three-dimensional curved surface.