If an equilateral triangle is inscribed in a circle of radious 8cm, what is the perimeter of the triangle?

Let O be the center of the circle and A,B,C be the vertices of the equilateral triangle. Draw line OA and a line from O perpendicular to AB. Call the intersection point M. Then triangle MAO is a 30-60-90 triangle because OA bisects 60 deg. angle A. Then side AM is 4 sqrt(3). since AB is twice as long as AM, AB=8 sqrt(3). then the perimeter of triangle ABC is 24 sqrt(3).