A curved surface on which all points are the same distance from the center is called a sphere.
circle
This is the center, or locus, of a set of points, such as a curve or circle.
A circle
"Radius" is a measurement that refers to a circle. It's the distance from the circle's center to any point on its curve.
... is called a Great Circle arc.
A circle.
The spelling "radios" is the plural of "radio."The geometry term radius is the distance from a circle (or sphere surface, or curve) to its center.
circle
This is the center, or locus, of a set of points, such as a curve or circle.
The distance from the fixed point at the center of a circle to any point on the curve is called the radius.
An imaginary line that follows the curve of the Earth is called a great circle. It represents the shortest distance between two points on the Earth's surface and is often used in navigation and mapping.
A circle
Since the surface of water rises up to the sides of the cylinder, the low point is in the center of the surface. (Volume is assumed unless boiling or melting points are stated)
The shortest distance between two points can be a curve when the path follows the geometry of the space, such as on a sphere or a curved surface where a straight line is not possible. This is because the curve minimizes the distance traveled while staying within the constraints of the space's geometry.
Diameter is the length of a straight line passing through the center of a circle or sphere and connecting two points on the circumference of the circle or the surface of the sphere. Circumference is the length of the closed curve of a circle.
Points on the Curve was created on 1984-01-16.
That refers to the center of the circle that "fits best" - that follows the direction of a curve (locally) most closely. (The formal definition, of course, is a bit more complicated, and involves concepts of calculus, such as limits.)