a circle.
Septahedron
== == An isosceles triangle with sides 5, 5, 3. The only line of symmetry is the line joining the midpoint of the side of 3 units to its opposite vertex.
A parallelogram
A closed wiggly line. or many irregular polygons such as scalene triangle, ordinary quadrilateral, trapezium (if not isosceles), etc.
The 2D shape which has one line of symmetry is the trapezium.
An isosceles triangle and a kite have only one line of symmetry.
A square
Square
a circle.
A 2d shape with uncountable lines of symmetry is a circle.
Ss
A triangle, an oval, a trapezoid as well I think.
Septahedron
1
septahedron
== == An isosceles triangle with sides 5, 5, 3. The only line of symmetry is the line joining the midpoint of the side of 3 units to its opposite vertex.