Final answer:
The step not needed to find the perimeter is using the slope formula to find the slope of each side, as perimeter calculations involve plotting the points, using the distance formula, and summing the lengths.
Step-by-step explanation:
The step that is not necessary for finding the perimeter of the figure determined by the points (-3, -5), (-2, 7), (4, 1), and (3, -6) is D) Use the slope formula to find the slope of each side. To calculate the perimeter, you do need to plot the points (A), use the distance formula (C) to find the length of each side, and then add the lengths of all sides together (B). The slope of each side is irrelevant for calculating perimeter, as the perimeter is simply a measure of the total distance around the shape.