Hi ukgmat,

I'm going to give you some hints so that you can try these questions again on your own:

For the first question, here are the math rules/patterns that you need to know:

1) Any time you see a diagonal line segment on a graph, you can draw a right triangle using that line as the hypoteneuse.
2) Right triangles on the GMAT are almost always pattern-based (angles or sides; at the very least, the Pythagorean Theorem). Here, we have a 1 and a √3, so we should be thinking 30/60/90.
3) Radii have the same length no matter what direction they go in.
4) Lines "add up" to 180 degrees.

For the second question, try drawing pictures. I bet that you can get tot he correct answer in under a minute.

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