A shape cannot have only one side because it would not be closed. A shape must have at least three sides to be a closed figure (no "gaps")
An oval and a circle both have 0 sides
a 0 sided shape is a circle
circle
the shape has 1 side of symmetry
It is not possible to have 1 parallel side since it must be parallel to another side. A four sided shape with 1 PAIR of parallel sides is a trapezium (or trapezoid).
Any curved shape such as a circle, an ellipse, an oval, a wriggly line - as long as it does not have any corners.
Cone....
Cone
a circle
Irregular shape is the term given to an object which has 1 flat side, 1 curved side, no corners but has curved edges.
A semicircle.
A two dimentional shape with 1 side and 1 vertex.
A line. Or a circle
A vertical line
A sphere
a quadrilateral
the shape has 1 side of symmetry
A semicircle is one shape fitting this description.
A cylinder.
A "Math Trapazoid" is a shape that has 4 sides. There is 1 long side on the bottom, 1 medium sized side on the top, and 2 equal slanted sides on the sides of the shape.