A line of symmetry in a regular pentagon must go from the center of any side to the vertex directly opposite to it because a regular pentagon has five sides it also has five lines of symmetry most regular polygons have a number of lines of symmetry that are equal to the number of its sides. Lines of symmetry of a regular pentagon. A regular pentagon has 5 sides and 5 lines of symmetry the number of lines of symmetry in a regular polygon is equal to the number of sides