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Parallel Lines and Transversals . Geometry Chapter 3, Section 3. Angles and Parallel Lines Activity. Using a ruler, trace over two of the parallel lines on your index card that are near the middle of the card and about an inch apart.
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Parallel Lines and Transversals Geometry Chapter 3, Section 3
Angles and Parallel Lines Activity • Using a ruler, trace over two of the parallel lines on your index card that are near the middle of the card and about an inch apart. • Draw a transversal that makes clearly acute and clearly obtuse angles near the center of the card • Label the angles with numbers from 1 to 8 • Sketch the parallel lines, transversal, and number labels in your notes. We will use this to record observations.
Angles and Parallel Lines Activity • Cut the index card carefully along the lines you first drew to make six pieces. • Try stacking different numbered angles onto each other and see what you observe. • Try placing different numbered angles next to each other and see what you Observe • Mark your observations on the sketch in your notes
Angles and Parallel Lines Activity • Answer the following questions • How many different sizes of angles where formed? • 2 • What special relationships exist between the angles • Congruent and supplementary • Indicate the two different sizes of angles in your sketch.
Angles and Parallel Lines Activity • How can we use the vocabulary learned yesterday, to describe these relationships? • IF parallel lines are cut by a transversal, THEN • corresponding angles are congruent (Postulate in Text) • alternate interior angles are congruent (Theorem in Text) • alternate exterior angles are congruent (Theorem in Text) • Consecutive Interior angles are Supplementary (Theorem in Text)
Perpendicular Transversal • In your notes, trace over two of the parallel lines about one inch apart. • Using a protractor, draw a line perpendicular to one of the parallel lines. • Extend this perpendicular so that it crosses the other parallel line. • Based on your observations in the previous exercise, what should be true about the new angles formed? • Verify this with your protractor. • If a line is perpendicular to one of two parallel lines, then it is perpendicular to the other. (Theorem in Text)