1. The problem statement, all variables and given/known data Find the Perimeter of an equilateral triangle inscribed in a circle knowing the radius r. 2. Relevant equations - 3. The attempt at a solution Browsing the web I found that the intersection of the three perpendicular bisectors of a traingle is the center of it's circumscribed circle. Knowing this I proceeded as following: [img=http://img214.imageshack.us/img214/2971/problem1bgc6.th.jpg] I think that what I did is correct. However, since I should've been able to solve it with what I already knew I thought that maybe there is another easier solution. Thanks.