AC = √[(-2-3)^2 + (6-2)^] = √[5^2 + 4^2] = √[25+16] = √41 =6.4
To find the perimeter you need the lengths of AB and BC.
You already know the points (-2,6) and (3,2)
Then you need the point B to apply the distance formula from B to each of those points.