**Chain Surveying is Suitable**

- Ground is fairly level and simple
- Plans are required on large scale e.g. fields
- When area is small in extent

**Chain Surveying is Not Suitable**

- For Large Areas
- When too many details are required
- Wooded countries
- Undulating areas

Since the triangle is a simple plane geometrical figure, it can be plotted from the measured length of its sides alone; therefore, the principle of chain survey is Triangulation.

In chain surveying, a network of triangles is preferred.

Preferably all the sides of a triangle should be nearly equal having each angle nearly 60 to ensure minimum distortion due to errors in measurement of sides and plotting.

Generally such an ideal condition is not practical always. Usually attempt should be made to have well-conditioned triangles in which no angle is smaller than 30 and no angle is greater than 120.