It is the circle's radius
A circle or a sphere would fit the given description.
Circle
Yes, all of the radii in a single circle are congruent.
Circle
To qualify as a function, for every value of "x" there must be but a single "y" value. This isn't the case with a circle.
That's called a "circle".
A circle is a set of points equidistant ( the same distance ) away from a single point, the center of the circle.
A circle or a sphere would fit the given description.
===> "circle", with center at the "single point" and radius of the "certain distance".
Circle
Circle
Parts of a circle include the diameter, circumference, radius, and center. The diameter of a circle is a chord passing through the center. The center is a single point at which the distance to locations on the circumference are equal. The circumference is the perimeter of the circle. The radius of the circle is half the diameter, and the distance from the center to a point on the outlying circumference.
There is no chord that is always smaller since, in the limit, the chord reaches a single point on the circumference - when it it is no longer a chord!
In geometry, a circle is a two-dimensional shape formed by all points that are one consistent distance or "radius" from a single central point. For example, if the radius is 5 inches, then the shape formed from the preceding rule would be a perfectly round circle measuring 10 inches in "diameter" (the distance of any one point on a circle to the farthest point on the same circle).
I've always called it "single, but unavailable"
A sector is basically just one portion of a circle. However, the sides of a vector are always two radii of the circle. If you are looking at a whole pie, and you portion off a single slice of pie, the single slice of pie would be considered a vector to the entire pie.
A circle doesn't have even a single vertex.