Answer:
23.56 length units
Explanation:
To calculate the perimeter of a triangle, we need to calculate the length of all the sides, then sum up the lengths.
To calculate each side, we take the differences of the coordinates of consecutive vertices, square, add, and take square-root (Pythagoras theorem).
Side 1: (3,-2), (5, -8)
difference in coordinates=(2,-6), length=sqrt(2^2+6^2) = sqrt(40)
Side 2: (5, -8), (-2,1)
difference in coordinates=(7,-9), length=sqrt(7^2+9^2) = sqrt(130)
Side 2: (-2,1), (3,-2)
difference in coordinates=(5,-3), length=sqrt(5^2+3^2) = sqrt(34)
Perimeter
= sum of sides
= sqrt(40)+sqrt(130)+sqrt(34)
= 6.32+11.40+5.83
= 23.56 approximately