Final answer:
The farmer needs to consider a rectangle as the geometric shape to fence in the plot of land.
Step-by-step explanation:
The geometric shape that the farmer needs to consider when fencing in a rectangular plot of land is c) Rectangle.
A rectangle is a four-sided polygon with opposite sides that are equal in length and 90-degree angles between them. It is the most suitable shape for the farmer to enclose the plot of land.
To determine the perimeter of the rectangle, the farmer needs to calculate the sum of the lengths of all four sides. The formula for the perimeter of a rectangle is P = 2L + 2W, where P is the perimeter, L is the length, and W is the width of the rectangle.
For example, if the length of the plot of land is 10 meters and the width is 5 meters, the farmer would calculate the perimeter as follows: P = 2(10) + 2(5) = 20 + 10 = 30 meters.