Answer:
8pi
Explanation:
Since the triangle is a 30-60-90 triangle, the hypotenuse is 2 times the shortest side and the second longest side is sqrt3 times the shortest side. Since it is given that the second longest side is 4sqrt3, this means that the shortest side is 4, so the hypotenuse is 8.
Because of this, the diameter is 8, which means the radius is half of the diameter, which is 4.
The formula for circumference is 2*pi*r, and since r is 4, we can plug this in to get 2*pi*4, which is 8pi.