How is geometry used in photography?

Answer 1

A little ambiguous - Im not sure what you mean by "used" in relation to the application creatively, as a subject or technically.

As a subject yes - geometric shapes and objects are photographed daily.

Creatively - The guideline called "the rule of thirds" is often considered when photographing. Other spacial and placement guidelines are also used.

Technically - I assume maths and geometry is used in the making and using of equipment such as cameras and tripod on various levels.

Answer 2

A good photographer will use the proper "angles" to bring out the best perspective for the subject. www.hottelphotography.com