Wikipedia Definition of Form:
Form may be described as any three-dimensional object. Form can be measured, from top to bottom (height), side to side (width), and from back to front (depth). Form is also defined by light and dark. It can be defined by the presence of shadows on surfaces or faces of an object. There are two types of form, geometric (man-made) and natural (organic form). Form may be created by the combining of two or more shapes. It may be enhanced by tone, texture and color. It can be illustrated or constructed.
Going out and finding design elements, taking a photo of it and then describing why it is an example is not as easy as it sounds. One thing about design is that the more simple it looks, the more complicated it probably is!
This photo shows form in the white geometric statues. They attracted my attention with being white and the snow that is round them at this time. The snow adds texture but also emphasizes the forms through contrast.