The situation is very similar when we attempt to express in mathematical symbols a condition proposed in words. First, we must understand thoroughly the condition. Second, we must be familiar with the forms of mathematical expression. The first rule of discovery is to have brains and good luck. The second rule of discovery is to sit tight and wait till you get a bright idea.
Geometry is the art of correct reasoning on incorrect figures.
If you have to prove a theorem, do not rush. First of all, understand fully what the theorem says, try to see clearly what it means. Examine the consequences, verify as many particular instances as are needed to convince yourself of the truth. When you have satisfied yourself that the theorem is true, you can start proving it. Mathematics consists of proving the most obvious thing in the least obvious way.