What are some Geometry terms that start with the letter "Z"?

Question

I need at least 6 words from Gemetry terminology that start with the letter "Z"!

Answer 1

I went to several places and found only these:

Zero angle
Zero-dimensional
http://library.thinkquest.org/2647/geometry/glossary.htm#z

To these I would add

zero-zero, or (0,0) the origin of the Cartesian system.
z-axis, the third axis in a three dimensional system.
z-intercept, the place on the z-axis where a line crosses it, z when x=0 and y=0
zero slope - the slope of a line that is parallel to the x-axis

This online math dictionary includes a few others that probably aren't used in geometry.
http://www.mathwords.com/wxyz.htm

Also, there is zenith. In astronomy, this is the point directly overhead. It's a push, but there are three coordinate systems used in astronomy, one that is Earth-centered and divided by the equator, one that is Sun-centered and divided by the ecliptic, and one which is viewer-centered and divided by the horizon. Translating from one system to another is a problem in three dimesional geometry.

Answer 2

Geometry Words A-z

Answer 3

butthole