Yes, a linear shape can be symmetrical.
A linear shape is symmetrical because it exhibits symmetry along a central axis. In the case of a linear molecule (as alluded to in the reference material), you can see that if you were to divide it in half along its central atom, the two halves would be mirror images of each other. This is reflective symmetry.
For example, consider a simple linear molecule like carbon dioxide (CO2). The molecule consists of a carbon atom bonded to two oxygen atoms in a straight line (O=C=O). If you were to draw a line perpendicular to the C=O bonds and through the center carbon atom, the two oxygen atoms would be symmetrical reflections of each other.
Therefore, linear shapes meet the criteria for being symmetrical.
