Using the distance formula:
AB^2 = (-2-6)^2 = (2-2)^2
= 64
AB = 8 units
BC^2 = (6-0)^2 + (2-8)^2
= 36 + 36
= 72
BC = 6 root 2
AC^2 = (-2-0)^2 + (2-8)^2
= 4 + 36
= 40
AC = 2 root 10
Perimeter = 8 + 6 root 2 + 2 root 10
= 2 (4 + 3 root 2 + root 10) units