Definition:Zone of Sphere

Definition

A zone of a sphere $\SS$ is a surface formed from the part of the surface of $\SS$ by two parallel planes intersecting $\SS$.

Base of Zone

Each of the two parallel planes defining a zone of a sphere $\SS$ is called a base of the zone.

Height of Zone

The height of a zone of a sphere $\SS$ is defined as the distance between the bases of the zone.

Zone of Two Bases

A zone of two bases is a zone of a sphere $\SS$ in which neither of the bases are tangent to $\SS$.

Zone of One Base

A zone of one base is a zone of a sphere $\SS$ in which exactly one of the bases is tangent to $\SS$.

Also see

• Results about zones of spheres can be found here.

Sources

• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): zone
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): zone