In Chapter 1, you will apply the big ideas listed below and reviewed in the Chapter Summary on page 59. You will also use the key vocabulary listed below.

Big Ideas 1 Describing geometric fi gures

2 Measuring geometric fi gures

3 Understanding equality and congruence

KEY VOCABULARY undefined terms, p. 2

point, line, plane

defined terms, p. 3

line segment, endpoints, p. 3

ray, opposite rays, p. 3

postulate, axiom, p. 9

congruent segments, p. 11

midpoint, p. 15

segment bisector, p. 15

acute, right, obtuse, straight angles, p. 25

congruent angles, p. 26

angle bisector, p. 28

linear pair, p. 37

vertical angles, p. 37

polygon, p. 42

convex, concave, p. 42

n-gon, p. 43

equilateral, equiangular, regular, p. 43

Now

Geometric figures can be used to represent real-world situations. For example, you can show a climbers position along a stretched rope by a point on a line segment.

Geometry The animation illustrated below for Exercise 35 on page 14 helps you answer this question: How far must a climber descend to reach the bottom of a cliff?

Other animations for Chapter 1: pages 3, 21, 25, 43, and 52

Geometry at classzone.com

Why?

3TART3TART #HECK!NSWER#HECK!NSWER

$ISTANCETHECLIMBERHASTODESCENDFEET

!

"

#

!#ISFEETAND!"ISFEET(OWMUCHFARTHERMUSTTHECLIMBERDESCENDTOREACHTHEBOTTOMOFTHECLIFF%NTERYOURANSWERINTHEBOXBELOWANDCLICKh#HECK!NSWERv

Use the given information to enter a distance. Then check your answer.

Your goal is to find the distance from a climbers position to the bottom of a cliff.

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