9514 1404 393
Answer:
18 units
Explanation:
The distance formula is used to find the distance between two points:
d = √((x2 -x1)² +(y2 -y1)²)
For AB, the distance is ...
d = √((0 -(-4))² +(-2 -1)²) = √(16 +9) = √25 = 5
The distances between the other pairs of points can be found the same way. We have elected to let a spreadsheet do the math. It tells us the perimeter of triangle ABC is 18 units.