Answer:
21.42
Step-by-step explanation:
The length of the diagonal sides of this parallelogram are given by the distance formula:
d = √((x2-x1)^2 +(y2 -y1)^2) = √((2-(-1))^2 +(8-2)^2) = √(3^2 +6^2) = 3√5
Of course, the lengths of the horizontal segments are given by the difference in their x-coordinates: 3-(-1) = 4. As with any parallelogram, the perimeter is twice the sum of adjacent side lengths:
P = 2(d +4) = 2(3√5 +4) = 8 +6√5 ≈ 21.4164
P ≈ 21.42 units
The perimeter is about 21.42 units.
