I really don't understand why my answer isn't right for this problem.

Let G denote the centroid of triangle ABC. If triangle ABG is equilateral with side length 2, then determine the perimeter of triangle ABC.

I drew a diagram and I got 2(sqrt13)+2, but the website that I got the problem from says that my answer is incorrect. Please help me with this as I could really use some guidance.

Thanks!

The answer is 2*sqrt(17) + 2.