Question

Wulun an object shows symmetry is called one.
2. A sequence of shapes that are arranged based upon a rule is called
3. A rectangle has 2 lines of symmetry.
n ais a two dimensional shane that can he folded to form 1​

Answer 1

Line of Symmetry
dog mirror


Here my dog "Flame" has her face
made perfectly symmetrical with a bit
of photo magic.

The white line down the center is the
Line of Symmetry

Read more at Reflection Symmetry.
Folding Test
You can find if a shape has a Line of Symmetry by folding it.

When the folded part sits perfectly on top (all edges matching), then the fold line is a Line of Symmetry.

Here I have folded a rectangle one way, and it didn't work.

symmetry folding no
So this is not a Line of Symmetry

But when I try it this way, it does work (the folded part sits perfectly on top, all edges matching):

symmetry folding yes
So this is a Line of Symmetry

Triangles
A Triangle can have 3, or 1 or no lines of symmetry:

symmetry equilateral triangle symmetry isosceles triangle no symmetry scalene triangle
Equilateral Triangle
(all sides equal,
all angles equal) Isosceles Triangle
(two sides equal,
two angles equal) Scalene Triangle
(no sides equal,
no angles equal)
3 Lines of Symmetry 1 Line of Symmetry No Lines of Symmetry
Quadrilaterals
Different types of Quadrilaterals (a 4-sided plane shape):

symmetry square symmetry rectangle symmetry irregular quad
Square
(all sides equal,
all angles 90°) Rectangle
(opposite sides equal,
all angles 90°) Irregular
Quadrilateral
4 Lines of Symmetry 2 Lines of Symmetry No Lines of Symmetry


symmetry kite symmetry rhombus
Kite
Rhombus
(all sides equal length)
1 Line of Symmetry 2 Lines of Symmetry
Regular Polygons
A regular polygon has all sides equal, and all angles equal:

symmetry equilateral triangle An Equilateral Triangle (3 sides)
has 3 Lines of Symmetry
symmetry square A Square (4 sides)
has 4 Lines of Symmetry
symmetry regular pentagon A Regular Pentagon (5 sides)
has 5 Lines of Symmetry
symmetry regular hexagon A Regular Hexagon (6 sides)
has 6 Lines of Symmetry
symmetry regular septagon A Regular Heptagon (7 sides)
has 7 Lines of Symmetry