<p>Power to a point
Area of a triangle = bh/2 = 1/2ab sin(theta) = rs</p>
<p>Sum of geometric series = 1/1-r</p>
<p>(s is semiperimeter)</p>
<p>Mhmm, area of a triangle was nice, specifically number 18 on this year’s AMC 12 A. :)</p>
<p>Also, area of a triangle = sqrt[s(s-a)(s-b)(s-c)] where a, b, c are the sides, and s=(a+b+c)/2. That helped. :)</p>
<p>Basically just go through AOPS Book Volume 1 (don’t bother w/ volume 2 yet) and do all the problems/go through the examples (and read, of course). But last minute studying isn’t really likely to qualify you for AIME. People usually study for AMC’s year round.</p>