This is a little bit like asking why a square has four sides. A regular pentagon is defined in such a way as to require that it has 5-fold rotational symmetry.
It has rotational symmetry of order 2.
Parallelograms: 2-fold Square: 4-fold n-fold symmetries refer to rotational symmetries. Consequently, any symmetries about axes that these and other quadrilaterals may have are not relevant to this question.
Yes A right-angled triangle may have 2 equal sides but only exhibits 1-fold rotational symmetry (ie it is not rotationally symmetric). However, I believe that any polygon in which each side is parallel to the opposing side must be at least 2-fold rotationally symmetric (ie it is rotationally symmetric).
It means 4 lines of symmetry as for example a square has 4 lines of symmetry
Yes, it does.
A regular pentagon or a 5-pointed star have rotational symmetry of order 5.
A line has rotational symmetry of order 2.
line
two-fold
A cube has 3-fold rotational symmetry, meaning it can be rotated by 120 degrees and still look the same. It does not have 5-fold rotational symmetry because the cube's faces are not oriented in a way that allows for that type of symmetry. The angles between the faces do not align with the requirements for 5-fold rotational symmetry.
It has rotational symmetry of order 2.
Are you referring to the Marquise Cut in Diamond jewelry? This is in the shape of a pointed oval; it would two-fold rotational symmetry.
A two-fold symmetry has a 360 degrees rotation. A three-fold rotational symmetry, on the other hand, has 120 degrees, and on a horizontal axis, a symmetry has 180 degrees.
Yes, because if you take a clover and fold it it will fold evenly like paper.
A shape with two-fold rotational symmetry looks the same after a rotation of 180 degrees. An example of this is a rectangle, which appears unchanged when rotated halfway around its center. Other shapes, like certain types of isosceles triangles and some polygons, also exhibit this symmetry. Essentially, any shape that can be flipped upside down and still match its original appearance has two-fold rotational symmetry.
An octagon has eight-fold rotational symmetry, because rotation of octagon by 45 degrees (one-eighth of a full circle) produces a figure that is superimposible on (or congruent to) the original.
A parallelogram has rotational symmetry of order 2.