The correct answer is: C. 1630
The method of surveying by triangulation was first introduced by the Dutchman Willebrord Snellius in 1630. Snellius was a mathematician and astronomer who is best known for his work on Snell’s law of refraction. He was also the first person to use triangulation to survey a large area.
Triangulation is a method of surveying that uses the angles between three or more points to determine the distance between those points. It is a very accurate method of surveying and is used for a variety of purposes, including mapping, construction, and engineering.
The method of triangulation is based on the principle that the angles of a triangle add up to 180 degrees. If you know the angles of two sides of a triangle and the length of one side, you can calculate the length of the other two sides.
Triangulation can be used to survey large areas by measuring the angles between three or more points that are visible from each other. The distances between the points can then be calculated using the law of sines.
The law of sines states that the ratio of the sine of an angle to the length of the opposite side is equal to the ratio of the sine of another angle to the length of the opposite side.
Triangulation is a very accurate method of surveying and is used for a variety of purposes, including mapping, construction, and engineering. It is a relatively simple method to use and can be used to survey large areas.
The other options are incorrect because they are not the year that Snellius first introduced the method of surveying by triangulation.