The sand patterns
in the Challenge were created by
the Tchokwe tribe of northeastern Angola.
Members of this tribe used these designs
for telling stories.
Dorothy Washburn and Donald Crowe have studied
linking of geometric patterns
to cultural identification.
Some African cultures, such as the Ndebele,
make decorations that use line symmetry. These
patterns contain no curves, in contrast to
the Angolan patterns in the Challenge.
Barnes is a designer who uses mathematics to
form patterns to weave into cloth
for her line of clothing.
Many entrance examinations
for higher education, including the Dental
Aptitude Test (DAT), include questions involving the recognition
and extension of patterns.