In
geometry and
science, a
cross section is the
intersection of a body in
three-dimensional space with a
plane, or the analog in higher-dimensional space. Cutting an object into slices creates many parallel cross sections. A cross section of three-dimensional space that is parallel to two of the
axes is a contour line; for example, if a plane cuts through mountains of a
raised-relief map parallel to the ground, the result is a contour line in two-dimensional space showing points of equal
altitude.