1. NM Standards: GT-A-7

2. Parallel Lines Coplanar lines that do not intersect. The symbol || means “is parallel to” The red arrows also mean “is parallel to” Parallel Planes Two or more planes that do not intersect. m n Lines m & n are skew lines Skew Lines Two or more lines that do not intersect but are not parallel. Skew lines are always on different planes.

3. Example 1-1a Name all planes that are parallel to plane AEF. Answer: plane BHG

4. Example 1-1b Name all segments that intersect Answer:

5. Example 1-1c Name all segments that are parallel to Answer:

6. Example 1-1d Name all segments that are skew to Answer:

7. Example 1-1e

9. Transversal A line that intersects two or more other lines in a plane at different points The two or more lines do NOT have to be parallel.

10. Example 1-2e HIKING A group of nature trails is shown. Identify the sets of lines to which each given line is a transversal. Answer: lines c, d, e, f Answer: lines a, b, d, e, f a. line a b. line b c. line c d. line d Answer: lines a, b, c, e, f

11. Types of Angles Exterior Angles: Angles that lie outside the lines cut by a transversal Interior Angles: Angles that lie between the lines cut by a transversal Consecutive Interior Angles: Pairs of interior angles formed by a transversal that lie on the same side of the transversal and share a side. Alternate Exterior Angles: Pairs of exterior angles formed by a transversal that lie on opposite sides of the transversal. Alternate Interior Angles: Pairs of interior angles formed by a transversal that lie on opposite sides of the transversal. Corresponding Angles: Pairs of angles formed by a transversal that lie on the same side of the transversal, but one is interior and one is exterior. Linear Pairs: Two angles whose non-common sides create a straight line

12. Example 1-3a Answer: corresponding Identify as alternate interior, alternate exterior, corresponding, or consecutive interior angles.

13. Example 1-3b Answer: alternate exterior Identify as alternate interior, alternate exterior, corresponding, or consecutive interior angles.

14. Example 1-3c Answer: corresponding Identify as alternate interior, alternate exterior, corresponding, or consecutive interior angles.

15. Example 1-3d Answer: alternate exterior Identify as alternate interior, alternate exterior, corresponding, or consecutive interior angles.

16. Example 1-3e Answer: alternate interior Identify as alternate interior, alternate exterior, corresponding, or consecutive interior angles.

17. Example 1-3f Answer: consecutive interior Identify as alternate interior, alternate exterior, corresponding, or consecutive interior angles.

18. Example 1-3g

19. hw #1: Page 128