Final answer:
To determine the area of a triangular piece of land, the lengths of two sides and the included angle are needed. Without the angle or additional information, the length and orientation of the third side C cannot be accurately determined.
Step-by-step explanation:
To determine the area of a polygon, specifically a triangular piece of land, the landowner must use the given lengths of two sides and the included angle. If the angle is not provided, it could involve more complex calculations or the application of trigonometric principles if the triangle is right-angled or if additional details are available that can help in establishing the missing values. If the triangle is not right-angled or other information is missing, the landowner may not be able to determine the third side using just the lengths of the two sides alone.
In the specific scenario where displacement vectors are mentioned, it is possible that vector addition is required to find the third side, or the landowner might be applying the law of cosines if the angle between the two vectors (sides of the land) is known. However, without the angle or a clear figure to refer to, we cannot provide an accurate length and orientation of the third side C.
The method of calculating the area under the graph does not apply to determining the length and orientation of the third side of a triangle unless the context of the question refers to vector displacements graphically represented.