Geometry

Memorize the Formulae

You can't get around it. You have to know the 30:60:90 triangle ratio. You'll be tested on the area of a circle. There are plenty of Geometry questions that you can't fake your way through--if you don't know that basic content, you'll miss them. They can be cheap points, but only if you do the work.

Apply the Formulae

This sounds obvious, but bear with me. It takes some time to learn all the rules, but once you know them, there isn't much that the test can keep hidden. If there are triangles in a question, there are only so many rules that could possibly apply.

If you're stuck on a geometry question, use the process of elimination. Think through all of the techniques you know that could possibly be relevant. One of them is probably what you need to use to solve the problem.