How is the number of lines of symmetry for a regular polygon connected to the number of sides of the polygon

Excluding some quadrilaterals, some polygons like a hexagon or square have the same amount of lines of symmetry as they do sides.

Answerthe simplified expression isexplanationthe given expression is,let us deal with the bracket first.the two negatives in the parenthesis will become positive.the expression now becomes,we now expand the parenthesis to get,we group like terms to obtain,this simplifies to,