Check the shape which is completely closed.

Try to draw a lines of symmetry across an rectangle.

Check the shape which is completely closed and imagine the unsymmetry for the same.

Check the shape which is completely closed and imagine the line of symmetry for the same.

Try to imagine a line of symmetry across these letters.

Try to draw a line of symmetry across an Butterfly

Try to draw a line of symmetry across all the shapes.

Try to draw a lines of symmetry across all the shapes.

Mind you ,there is a difference between number of lines of symmetry of a square and a rectangle.

Check the shape which is completely closed.