Explanation

 Calculating the area of an irregular shape might involve several methods of approximation or computational geometry. 

The best approach will depend on the tools available and the level of precision required for the task.

Explanation

 In chain surveying, the area is divided into a network of triangles, as triangles provide the simplest and most stable geometric figures for accurate measurements

Explanation

 Taken on a known point (like a benchmark).

It’s the starting reading for a new instrument setup.

Used to determine the height of the instrument (H.I.).

Explanation

 An alidade is a straightedge with sighting devices (like vanes or a telescope) used in plane table surveying.

It helps in aligning and drawing lines of sight from the station point to various objects in the field directly on the drawing sheet.

Explanation

 It represents the lateral displacement between the centers of gravity of the cut and fill areas.

Important in mass haul diagrams and balancing earthworks.

Helps optimize the movement of material (cut to fill) during road or railway construction.

Explanation

 A compass is used in plane tabling to orient the table by aligning it with the magnetic north, ensuring accurate plotting of directions and angles on the sheet.

Explanation

 The north line of a map is typically marked on the compass rose or north arrow.

This symbol indicates the direction of north and helps readers orient themselves in relation to the map's features.

Explanation

 Used when shifting the level instrument to a new position.

Ensures continuity in levelling.

Acts as a reference between two setups of the instrument.

Explanation

 Purpose: Measures vertical distance from the instrument line of sight to the ground.

Material: Usually made from aluminum or fiberglass; lightweight and durable.

Length: Generally 4 to 5 meters (around 13 to 16 feet), often telescopic for easy transport.

Types:

Self-reading staff (most common)

Target staff (has a sliding target for precise reading)

Explanation

 Held by hand or with a bubble level attached to ensure verticality.

If tilted, the reading becomes longer and inaccurate.

The staff person may use a plumb bob or circular bubble for precision.