We need to find the lengths of ab, bc and ca then add them up.
ab = sqrt ( -root3 ^2 + 3^2) = sqrt 12
bc = sqrt ( 3^2 -0^2 + (-root3)^2- 0^2) = sqrt 12
ca = sqrt ( 3^2 + root3^2) = sqrt 12
So the Perimeter = 3 sqrt 12 = 3 * 2 * sqrt3 = 6 sqrt3 ANSWER
