There are various kinds of methods and they are all based on a method known as “triangulation”. If one knows one side and two angles of any triangle (or two sides and one angle), one can find out the rest of its measurement. Whether the land one wants to measure is a hectare or 1000 hectares, the method of measuring is the same. One begins by measuring one distance very accurately with a chain, steel or wire.
This now becomes the side of the first triangle and is usually a level piece of ground between two landmarks. Now select a third landmark and make this the apex of the triangle. Then the angle it makes with each end of the first line is measured. These are the requirements for measuring the area of the triangle as described above (one side and two angles of a triangle).
The instrument for measuring these angles is called a transit; with the area of one triangle the land to be measured into triangles should be divided until the area of the entire piece of land. The transit works vertically which is called leveling as there is a spirit level at the base of the instrument that indicates when it is in level. By raising the sight to any landmark on a mountain, the same process of measuring angles can be done and the length of one side (the height) can be measured.