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# Chapter 6: Geometry and Transformations

Difficulty Level: Basic Created by: CK-12

## Introduction

Here you will learn some basic topics of geometry. First you will learn all about angles, including identifying types of angles and measuring angles. Then you will learn how to classify polygons. Next you will learn the concepts of congruence and similarity as they relate to geometry. Finally, you will learn about the geometric transformations of reflection, translation, rotation, and dilation, and you will see how these transformations relate to congruence and similarity.

## Summary

You learned that two angles are complementary if the sum of their measures is 90\begin{align*}90^\circ\end{align*} and two angles are supplementary if the sum of their measures is 180\begin{align*}180^\circ\end{align*}. You also learned to identify vertical angles and that vertical angles are always congruent. You then learned about lines and how lines can be parallel, perpendicular, or neither.

Next you focused on polygons, and learned how to accurately classify triangles, quadrilaterals, and other polygons. You learned that two shapes are congruent if they are exactly the same shape and the same size. Two shapes are similar if they are exactly the same shape but not necessarily the same size.

Finally, you learned about the geometric transformations of reflection, rotation, translation, and dilation. You learned that reflections, rotations, and translations all produce congruent shapes, while dilations produce similar shapes. You also learned about tessellations, and how to determine whether or not a regular polygon will tessellate.

Basic

Jan 23, 2013