# Geometry There are many basic concepts from Geometry that are used in Algebra, Trigonometry, and Calculus. Here are some simple formulas for commonly seen flat shapes:

 Triangle three sides A = ˝ bh A = area, b = base,  h = height Parallelogram four sides, opposite sides are parallel A = bh A = area, b = base,h = height Trapezoid four sides, top and base are parallel A = ˝(a+b)h A = area, a = top,b = base, h = height Circle all points the same distance from the center A = πr2 C = 2πr A = area, r = radius C = circumference

Three dimensional shapes are used all the time in practical applications. The abbreviations used for these formulas are:

 S = surface area V = volume B = area of base (use formulas above) h = height r = radius s = distance tip to base on a cone

Instead of area, with solids you want to find the surface area S and the volume V of the object.

Any Cylinder or Prism parallel bases V = Bh
Right Circular Cylinder base and sides form a right angle V = πr2h
S = 2πrh
Any Cone or Pyramid any shape base
 V = 1 Bh 3
Right Circular Cone point to center point of base forms a right angle
 V = 1 πr2h 3 S = πrs
Sphere all points the same distance from the center
 V = 4 πr3 3 S = 4πr2 ## Quick Review of your book

Postulates, Theorems, and Corollaries - a complete list of all postulates, theorems, and corollaries to theorems presented in the book begins on page R1 (after page 810) and it has purple edges to its pages.

Important vocabulary - in the book important words are highlighted in yellow. You should write these down in your Notables book or on a Foldable. An English and Spanish glossary starts on page R9 that gives definitions and a reference back to a page in the book. The Glossary has purple edges on its pages. Many of the glossary words from your book are also listed here.

Student Handbook - beginning on page 727 with green edges on its pages, this provides a good review of things you should have learned in math before beginning Geometry. There is an excellent review of graphing and basic Algebra.

Selected Answers – beginning on page R29 also has green edges on its pages. This section provides answers to odd problems for exercises, practice quizes, and the chapter reviews. Use these to check your own work to make sure you understand how to do the assignments. Comments, questions, or you just need some help? Send an e-mail to Mrs. Shearer Last Updated: 07/15/2011