2. A definition of parallel lines is "two coplanar lines that never intersect." Imagine railroad tracks or the strings on a guitar. Another way to think about parallel lines is that they extend in exactly the same direction. Or to say it more mathematically, if a third line intersects one line in a right angle and intersects a second line in a right angle, then the first and second lines are parallel. Use this last definition as the final step in a paragraph proof of the following. Given: The sum of the angle measures in any triangle is 180°; Z1 = 22 Prove: AB and CD are parallel lines. (Hint: First draw line AE so it forms a 90° angle with AB. This step can be justified by the Protractor Postulate. On the figure, label the intersection of AE and CD point F.) B

2. A definition of parallel lines is "two coplanar lines that never intersect." Imagine railroad tracks or the strings on a guitar. Another way to think about parallel lines is that they extend in exactly the same direction. Or to say it more mathematically, if a third line intersects one line in a right angle and intersects a second line in a right angle, then the first and second lines are parallel. Use this last definition as the final step in a paragraph proof of the following. Given: The sum of the angle measures in any triangle is 180°; Z1 = 22 Prove: AB and CD are parallel lines. (Hint: First draw line AE so it forms a 90° angle with AB. This step can be justified by the Protractor Postulate. On the figure, label the intersection of AE and CD point F.) B

Elementary Geometry For College Students, 7e

7th Edition

ISBN:9781337614085

Author:Alexander, Daniel C.; Koeberlein, Geralyn M.

Publisher:Alexander, Daniel C.; Koeberlein, Geralyn M.

Chapter7: Locus And Concurrence

Section7.1: Locus Of Points

Problem 47E: In Exercises 39 and 42, refer to the line segments shown. Use the following theorem to construct a...

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