In this lesson, we will show when to take advantage of symmetry. If the geometry, material orientation, loading, and expected response all exhibit symmetry about the same planes, we can take advantage of planar symmetry and only model a portion of the actual structure to reduce analysis run time and memory requirements. Using Symmetry Regions in Ansys Mechanical can give more accurate and more computationally efficient solutions. However, the Symmetry Region tool should not be used when all four symmetry requirements are not satisfied, such as in modal or linear buckling analyses where non-symmetric modes are needed to be calculated. We will give a short lecture, then get into Mechanical to illustrate the concepts on a mechanical part.