Units - Introduction

Basic of traditional or typical plane surveying are:
1. horizontal distances,
2. vertical angles,
3. zenith angles,
4. horizontal angles,
5. vertical distances,
6. slope distances.

Most common employed units are:
1. length,
2. area,
3. volume,
4. angle.

Two different systems are use in specifying of measured quantities:
1. English system,
2. Metric system (International System of Units - SI)