CK-12 Geometry-Concepts

http://www.ck12.org Chapter 1. Basics of Geometry

MEDIA

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URL: http://www.ck12.org/flx/render/embeddedobject/80768

CK-12 Foundation: Chapter1CongruentAnglesandAngleBisectorsB

Vocabulary

When two geometric figures have the same shape and size then they arecongruent. Anangle bisectoris a ray that
divides an angle into two congruent angles, each having a measure exactly half of the original angle.

Guided Practice

For exercises 1 and 2, copy the figure below and label it with the following information:

1.^6 A∼=^6 C

2.^6 B∼=^6 D

3. Use algebra to determine the value of d:

Answers:

1. You should have corresponding markings on^6 Aand^6 C.


2. You should have corresponding markings on^6 Band^6 D(that look different from the markings you made in #1).


3. The square marking means it is a 90◦angle, so the two angles are congruent. Set up an equation and solve:

7 d− 1 = 2 d+ 14

5 d= 15

d= 3

Interactive Practice