The first rule of life? Life (as well as geometry) can be difficult. But why make it more difficult than it has to be? Do you need help with geometry? Here are some tried-and-true tips to make your forays into the world of geometry as painless as possible.
Use a clear plastic protractor
Tools are fun, and the dandy protractor is no exception. The clear plastic kind is especially handy because you can see through it. That way, you can extend your angles right through the scale of the protractor. Reading angle measures is much easier then.
Use a clear plastic ruler with inches and centimeters
Just as with a clear plastic protractor, with a clear plastic ruler, you can extend your lines, which makes getting their measures easier. Using a ruler with inches and centimeters is a good idea. Go metric, baby!
Get a good pencil to draw fine lines
You need a pencil to make accurate drawings. Try to find a technical drawing pencil with a .05 mm lead. An eraser is an important commodity, also. You won’t regret getting one that has a brush. Eraser residue leaves the page easier when it’s brushed away.
Write down your givens and wants
When you’re setting up to solve a problem, be it a proof or just an equation, write down everything you’re given to work with even if it doesn’t seem important. The smallest details can lead to the biggest revelations. After you finish with what you’ve been given, move on to what you want. Write that down, too.
Make diagrams
A picture is worth a thousand words. Make a diagram with your awesome technical pencil. Try to draw things in proportion, keeping your spatial relationships intact. Mark off everything in the drawing that is in your given. If you have congruent lines, congruent angles, or parallel lines, mark ’em.
Read through the statements
This suggestion works best with completed proofs — proofs actually completed by someone else, like in a book about geometry. Read through the numbered information in the Statements column. Try to figure out what the reason should be for each statement. Check to see whether you’re correct. —Source: Dummies

Mark Ryan