It could be a circle or a sphere
A circle (2D) or a sphere (3D)
If your asking "What is ...?" Then, the answer is a circle. This is the definition of a circle!
line
A line.
They are parallel lines
Math
A circle (2D) or a sphere (3D)
If your asking "What is ...?" Then, the answer is a circle. This is the definition of a circle!
All points equidistant from a center point.
line
parabola
A line.
Parabola - apex
The bisector of that angle.
They are parallel lines
It depends on how many dimensions you are asking about. If you are talking about a 2-dimensional figure then it would be a circle. The definition of a circle is the collection of points that are equidistant from the center. If you are talking about a 3-dimensional figure, then it would be a sphere. The definition of a sphere is the collection of points in three dimensions that are equidistant from the center.
A rounded figure that has all surface points equidistant from the center is a sphere. A common object that is a sphere is a tennis ball.