Presentation on theme: "Parallel Lines and Transversals"— Presentation transcript:
1 Parallel Lines and Transversals Honors GeometryChapter 3, Section 1
2 Notes What does it mean for two lines to be parallel? Parallel lines: Lines that do not intersect and are coplanar.What about lines that don’t intersect and aren’t coplanar?Skew Lines: Lines that do not intersect and are not coplanar.What does it mean for two planes to be parallel?Parallel Planes: planes that do not intersect.Example: the planes containing the ceiling and floor are parallel
3 Notes Transversal: a line that intersects two or more lines in a plane at different points.E.g. Line c is a transversal to lines a and b.Line b is a transversal to which two other lines?a & cHow about line a?b & cWhen a transversalintersects two lines,how many angles areformed?8 angles are formed
4 Notes Angles formed by a transversal. We give certain pairs of these angles special names.Corresponding Angles: 1 & 5 ; 2 & 6 ; 3 & 7 ; 4 & 8Exterior Angles: 1, 2, 7, & 8Interior Angles: 3, 4, 5, 6Alternate Exterior Angles: 1 & 7 ; 2 & 8Alternate Interior Angles: 3 & 5 ; 4 & 6Consecutive Interior Angles: 4 & 5 ; 3 & 6
5 Notes Symbols for parallel in statements and figures The symbol ll means is parallel toThe pink arrows on lines PQ and RS indicate that they are parallel.
6 Angle Pair Names Activity Using about ¼ of a piece of binder paper, draw three lines so that one intersects two of the others.Color the exterior angles all one colorColor the interior angles all one colorLabel the exterior and interior anglesUsing another ¼ of a piece of binder paper, draw three lines so that one intersects two of the others.Color each pair of corresponding angles a different color.Label this quarter sheet of paper “corresponding angles.”Color each pair of alternate exterior angles a different color.Color each pair of alternate interior angles a different color.Label this quarter sheet “alternate exterior and interior angles.”Using the final ¼ of a piece of binder paper, draw three lines so that one intersects two of the others.Color each pair of consecutive interior angles a different color.Label this quarter sheet “consecutive interior angles.