# 3-D

3-D
3-D (or 3D) means three dimensional, or having three dimensions. For example, a box is three dimensional, it has up and down, left and right, and front and back. Some people believe there could be one dimensional or four dimensional objects but have not discovered any.
A dimension is measurable in inches, centimeters, miles, kilometers, or any other unit of length.
The three dimensions are called length (or depth), width (or breadth), and height.
3D is also used to make video games or animated movies. A lot of calculations are needed to make pictures seem three dimensional on a screen.
Mathematical dimensions.
In mathematics (maths), length, width, and height are given letters to make them easy to write. X is width, Y is height, and Z is length.Mathematic study of dimensions is called Geometry. Geometry can be used to measure how tall a mountain is.
Time.
Some people see time as a forth dimension. It is also measured. It is measured in units of time such as seconds, hours, years, or any other measurement of time.
Space.
Scientists hope that a fourth dimension will be discovered that will be a shorter distance between two places that are three dimensional. If travelling to distant stars and planets was possible in a short time it could be very useful.
Religion.
Most spiritual believers think something exists that is a part of everything else. Anything that is one dimensional would be a part of everything.
Dimensions in speech.
Other ways to use dimensions in speech can be: One dimensional (only interested in one thing), and Two dimensional (some people believe one thing, some people believe another one thing, and altogether they are interested in two things only)