Axis: It is the imaginary line
on which the semicircle that forms the sphere rotates.
Center: It is the equidistant
point to any point of the contour of the sphere, that is, of the spherical
surface.
Radius (Segment AD): It is the
distance between the center and any point of the spherical surface.
Chord: It is the segment that
joins any two points of the spherical surface.
Diameter (Segment BC): It is
that string that has the peculiarity of passing through the center of the
sphere. Its length is twice the radius.
Axis: It is the imaginary line
with respect to which the semicircle that forms the sphere rotates.
Meridians: They are the circumferences
that are obtained by cutting the sphere with planes that house the axis.
Parallels: They are the
circumferences resulting from cutting the sphere with planes that are
perpendicular to the axis (that cut the axis forming an angle of 90º).
Ecuador: It is the
circumference obtained by cutting the sphere with a plane perpendicular to the
axis and which, in turn, contains the center of the figure. It can also be
defined as the parallel with the greatest length.
Poles (Point B and Point C):
These are the points of the axis located at the top and bottom of the spherical
surface.
(Westreicher, December 22, 2020)
