Let O be a point with three other points A, B, C and \angle A O B=\angle B O C=\angle A O C=2 \pi / 3. Consider the average area of the set of triangles A B C where O A, O B, O C \in\{3,4,5\}. The average area can be written in the form m \sqrt{n} where m, n are integers and n is not divisible by a perfect square greater than 1 . Find m+n.