# Geometry Introduction

# Basic Elements

The basic elements of geometry are objects you see every day but probably never think about (unlike your Nintendo DS, which you think about every day and still can't seem to find). We're talking about **lines**, **angles**, and **shapes**—and lots of 'em.

That being the case, geometry will require you to draw sometimes. In fact, one of the best things to do if you're ever unsure about a geometry problem is to draw a picture. You don't have to be the next Claude Monet or Andy Warhol, but we'd advise you to steer clear of the Pablo Picasso Salvador Dali neck of the woods.

You'll also use **proofs**, fact-based arguments that lead to a logical conclusion, to dissect and discover the properties of these shapes. Chances are good that you've probably never written a proof before, so we'll cover exactly what proofs are and how best to tackle them. (Hint: get a running start.)

While geometry does primarily work in the visible arena, we'll still need the math tools we've been gathering so far. Hopefully addition, subtraction, multiplication, and division go without saying, but we said them anyway just to be safe. Basic **algebra** will definitely come in handy also—especially using linear equations and manipulating variables.

We'll also touch on **coordinates** and the *x*-*y* plane (and even the *x*-*y*-*z* plane), so we're hoping you kept the distance formula in a safe somewhere. If not, don't worry your pretty little head since it comes from the Pythagorean theorem anyway.