Correct Answer - Option 1 : Triangulation
A geodetic survey determines the precise position of permanent points on the earth's surface, taking into account the shape, size and curvature of the earth. .
It is done by Triangulation.
Triangulation is a surveying method that measures the angles in a triangle formed by three survey control points. Using trigonometry and the measured length of just one side, the other distances in the triangle are calculated.
Trilateration, method of surveying in which the lengths of the sides of a triangle are measured, usually by electronic means, and, from this information, angles are computed.
The triangulation and Trilateration are similar to each other but only difference is that in Trilateration all three side of triangle are measured and using trigonometry angles are computed but in triangulation angles are measured and using trigonometry side lengths are calculated.