They're free, use as many as you want.
It would help for you to tell us what specific object you're asking about.
One.
a rectangle has 2 axes of symmetry
A rectangle has 2 axes of symmetry.
There are infinitely many axes of symmetry in mathematics.
A square has 4 axes of symmetry.
It has 5 axes of symmetry
A regular pentagon has five axes of symmetry.
An isosceles triangle definitely has three axes of symmetry
A polygon need not have any axes of symmetry. It can have at most n axes where n is the number of sides that the polygon has.
Not sure about a duodecagon, but a regular dodecagon has 12 axes of symmetry.
perpendicular through any vertex. so there are three axes of symmetry.
10 axes of symmetry