There are several versions for various textbooks for the Pearson Education answer key for geometry for teachers available on Amazon. It is also possible to directly download a PDF copy via a user website.
Pearson does not sell answer keys for the geometry textbooks directly to the public; however, they do sell answer keys for other subjects, such as English. A search on their site can show a person what is available. There is also the possibility of contacting Pearson directly for additional assistance in locating a particular textbook and the textbook's answer key.
For a free version of the Pearson Education answer key for geometry, Koriobook is an online forum that offers PDF direct downloads of several Pearson answer keys. There is no guarantee that the site will have what a person needs, however, as it is a user-created forum.