i think we can take central angle of regular hexagon and by angle in a segment=half central angle we can judge whether the triangle is equilateral or not
I don't suppose you made a sketch . . .
Three of the six vertices of regular hexagon are chosen at random.
Find the probability that the three vertices form an equilateral triangle.
Three vertices can be chosen as 6C3. . Right!
After that, what to do?
There are only two equilateral triangles: . and