Final answer:
The process to calculate the elevation of an unknown point by using a known point is called triangulation. Triangulation is a method used in surveying and navigation to determine the distance or elevation of a point by measuring angles from two known points to the unknown point.
Step-by-step explanation:
The process to calculate the elevation of an unknown point by using a known point is called triangulation. Triangulation is a method used in surveying and navigation to determine the distance or elevation of a point by measuring angles from two known points to the unknown point. By drawing a triangle between the two known points and the unknown point, the elevation of the unknown point can be calculated using trigonometry.