I believe that is the definition of a straight line.
a straight line ..
A line in 2D and a plane in 3D A perpendicular bisector of the line connecting the 2 given points
A Circle.
you dont
A plane midway between the two given planes and parallel to them.
a straight line ..
A line in 2D and a plane in 3D A perpendicular bisector of the line connecting the 2 given points
A Circle.
A line that is the angle bisector.
you dont
A plane midway between the two given planes and parallel to them.
The center of the circle. That's how the circle is defined. (The collection of all points on a plane equidistant from a fixed point. The fixed point is the center and the fixed distance is the radius.)
That set of points forms what is known as a "circle".
It's another line, parallel to both of the first two and midway between them.
The center of a circle is an example of a point equidistant from all points on the circle's circumference, serving as the geometric midpoint of the shape. It is a key element for defining the circle's properties and relationships with other geometric figures.
The set of all points in the plane equidistant from one point in the plane is named a parabola.
I assume that you are asking about the definition of a circle. A circle is a locus of points in a plane that are at a constant distance from a fixed point.