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It may seem that there’s a lot to memorize in this chapter. But having defined terms yourself, you’re more likely to remember and understand them. The key is to practice using these new terms and to be organized. Do the following exercises, then read Assessing What You’ve Learned for tips on staying organized.

Whether you’ve been keeping a good list or not, go back now through each lesson in the chapter and double-check that you’ve completed each definition and that you understand it. For example, if someone mentions a geometry term to you, can you sketch it? If you are shown a geometric figure, can you name it? Compare your list of geometry terms with the lists of your group members.

EXERCISES

Answers to all exercises in every Chapter Review are provided in the back of the book. For Exercises 1–16, identify the statement as true or false. For each false statement, explain why it is false or sketch a counterexample. 1. The three basic building blocks of geometry are point, line, and plane. 2. “The ray through point P from point Q” is written in symbolic form as PQ. 3. “The length of segment PQ” can be written as PQ. 4. The vertex of angle PDQ is point P. 5. The symbol for perpendicular is . 6. A scalene triangle is a triangle with no two sides the same length. 7. An acute angle is an angle whose measure is more than 90°. 8. If AB intersects CD at point P, then a pair of vertical angles. APD and APC are

9. A diagonal is a line segment in a polygon connecting any two nonconsecutive vertices. 10. If two lines lie in the same plane and are perpendicular to the same line, then they are parallel. 11. If the sum of the measures of two angles is 180°, then the two angles are complementary. 12. A trapezoid is a quadrilateral having exactly one pair of parallel sides. 13. A polygon with ten sides is a decagon.

90 Chapter 1

Introducing Geometry

© 2008 Key Curriculum Press