Lines of symmetry must be equal halves.
rectangles
Providing that it is a regular 9 sided nonagon it will have 9 lines of symmetry
A hexagon has 6 lines of symetry and a dodecagon has 12. The number of sides equal the number of ines of symetry
Square, rectangle, rhombus
Regular polygons.
Lines of symmetry must be equal halves.
ractangle
rectangles
squares and rectangles
All regular ones do.
Providing that it is a regular 9 sided nonagon it will have 9 lines of symmetry
A hexagon has 6 lines of symetry and a dodecagon has 12. The number of sides equal the number of ines of symetry
If you're talking about convex polygons with equal sides (eg. equilateral triangles, squares, pentagons, hexagons, etc.), then the relationship is a very direct one. In those cases, there are as many lines of symmetry as there are points in the polygons. A triangle has three lines of symmetry, a square has four, a pentagon five, etc.
Square, rectangle, rhombus
rhombus, rectangle etc.
The number of lines of symmetry in a polygon corresponds to the number of sides it has. If a polygon has n sides, then its symmetry will be n lines of symmetry and it will have one point of symmetry. A pentagon has five lines of symmetry, nonagon has 9, n-gon has n lines of symmetry, so on and so forth.