Normally a straight line segment.
A chord is a line segment between two points on a given curve. Basically it's two points that are connected with a line which all happens to be on a curve. Most likely a circle
sphere
All points less than 3 distant from point 'P' comprise a circle, centered at 'P', with a radius of 3, but NOT including the line that is the circumference of the circle.
Circle
Normally a straight line segment.
A sphere is a solid bounded by the set of all points at a given distance from a given point.
A chord is a line segment between two points on a given curve. Basically it's two points that are connected with a line which all happens to be on a curve. Most likely a circle
A circle is the set of all points in a plane at a given distance FROM a given point, which is known as the circle's center.
line
The set of all points a given distance from a center point is a circle. The given distance is the radius, and the given point is the center. Or, in 3 dimensional space, a sphere.
sphere
Straight line
All points less than 3 distant from point 'P' comprise a circle, centered at 'P', with a radius of 3, but NOT including the line that is the circumference of the circle.
The set of all points a given distance from a center point is a circle. The given distance is the radius, and the given point is the center. In 3 dimensional space, the set would be the surface of a sphere.
Circle!
a circle, centered at the given point.