This paper reports part of an ongoing investigation into aspects of pre-service teachers' geometric knowledge. One hundred and fifty-two Australian pre-service teachers responded to a series of questions that reflect the type of knowledge teachers are expected to know and teach. Analysis of their responses shows that teacher knowledge can be understood through the interplay between individual teachers' formal figural concepts and personal figural concepts. Errors and misconceptions of geometric properties can be addressed by strengthening the link between formal and personal knowledge through visualisation.