It is a line segment.
It is the set of all points [from some fixed point] at a distance of 1 unit, where the points on the surface of the sphere are included in the set.
A solid sphere perhaps?
this is called a line.
The solution set is the set of all points representing solutions.
A sphere.
This set of points forms a circle with the fixed point as its center.
That set of points forms what is known as a "circle".
an ellipse.
A set of all points is how various shapes are made in geometry. Lines are sets of points, and so are surfaces. Circles are sets of all points that are a fixed distance from a central point. All geometric shapes are made from sets of all points.
the set of points equidistant from a fixed point
That's false
It is the set of all points [from some fixed point] at a distance of 1 unit, where the points on the surface of the sphere are included in the set.
A circle.
The set of all points in a plane for which the sum of the distances to two fixed points equals a certain constant. - APEX
corner...?
A circle is the set of all points in two dimensional space that are at the same distance from some fixed point.
It is the set of all points that are at a distance of 1 cm from a fixed point (called the centre).