AMSCO'S Geometry. New York - Rye High School

10 Essentials of GeometryEXAMPLE 1On a number line, the coordinate of A is 7 and the coordinate of B is 4. FindAB, the distance between A and B.SolutionThe distance between A and B is the absolute value of the difference of theircoordinates.AB 5 (27) 2 45 2115 11 AnswerEXAMPLE 2R, T, and S are three points on a number line. The coordinate of R is 3, the coordinateof T is 7, and the coordinate of S is 9. Which point is between the othertwo?SolutionSince 7 3 9, R is between T and S. AnswerNote: We can state in symbols that R is between T and S by writing TRS.ExercisesWriting About Mathematics1. Explain why “A hammer is a tool” is not a good definition.2. Explain why “A hammer is used to drive nails” is not a good definition.Developing SkillsIn 3–7: a. Write the definition that each phrase describes. b. State the class to which each definedterm belongs. c. Tell what distinguishes each defined term from other members of the class.3. noncollinear set of points4. distance between any two points on the number line5. line segment6. measure of a line segment7. congruent segments