Hi!
The following problem:
A circle is circumscribed about an equilateral triangle of side a, what is the diameter of the circle?
Well, i thought that the diameter could be used for constructing a right triangle with side a and the diameter as the hypothenuse, thus constituting a 30 : 60 : 90 triangle with the sides x, xRoot3 and 2x.
So my answer is 2a...unfortunately this is not among the answer choices...:(
any ideas!
Christian