Introduction
We live in a three-dimensional world. Every object you can see or touch has three dimensions that can be measured: length, width, and height. The room you are sitting in can be described by these three dimensions. The monitor you're looking at has these three dimensions. Even you can be described by these three dimensions. In fact, the clothes you are wearing were made specifically for a person with your dimensions.
In the world around us, there are many three-dimensional geometric shapes. In these lessons, you'll learn about some of them. You'll learn some of the terminology used to describe them, how to calculate their surface area and volume, as well as a lot about their mathematical properties.
In a combined operation, the navy
and airforce have a helicopter and
submarine at the levels shown:
Helicopter: 230 m above sea level
Submarine: 80 m below the surface of
the ocean, directly under
the helicopter
A parachutist from the helicopter has
76 m to fall before hitting the ocean.
a How far is the parachutist from the
submarine?
b What distance from the helicopter is she?
c How far apart are the helicopter and
submarine?