Hi sud21,

I'm going to give you a couple of 'hints' about how to deal with this question, so that you can retry it on your own:

1) Since you're given the circumference, you can figure out the RADIUS of the circle.
2) Draw a circle with the 6 EQUALLY-SPACED monuments on the circumference.
3) Draw a radius out to each monument and draw the "paths" between each pair of monuments (you now have 6 triangles).
4) Since a circle is 360 degrees, what is the measurement of the 6 central angles in your drawing?
5) What does that central angle tell you about ALL of those triangles that you just drew?

GMAT assassins aren't born, they're made,
Rich