A sphere
A vertical line
a quadrilateral
Spherical
A mobius loop which has one side and just one edge, could be your answer. Otherwise, a straight line segment may be it?
a circle
A line. Or a circle
A vertical line
a quadrilateral
Irregular shape is the term given to an object which has 1 flat side, 1 curved side, no corners but has curved edges.
A cylinder.
Any curved shape such as a circle, an ellipse, an oval, a wriggly line - as long as it does not have any corners.
Spherical
A mobius loop which has one side and just one edge, could be your answer. Otherwise, a straight line segment may be it?
sphere
a circle
A semicircle is one shape fitting this description.
Circle mobius strip