1 / 11

3.1 Lines and Angles

3.1 Lines and Angles. Mr. Davenport Fall 2009. Objectives:. Objectives: Identify relationships between lines. Identify angles formed by transversals. Definitions. Parallel lines – Two lines are parallel lines if they are coplanar and do not intersect.

dillan
Download Presentation

3.1 Lines and Angles

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. 3.1 Lines and Angles Mr. Davenport Fall 2009

  2. Objectives: Objectives: • Identify relationships between lines. • Identify angles formed by transversals.

  3. Definitions • Parallel lines – Two lines are parallel lines if they are coplanar and do not intersect. • Skew lines—Lines that do not intersect and are not coplanar. • Parallel planes—two planes that do not intersect.

  4. Think of each segment in the diagram. Which appear to fit the description? Parallel to AB and contains D Perpendicular to AB and contains D Skew to AB and contains D Name the plane(s) that contains D and appear to be parallel to plane ABE Example 1: Identifying relationships in space B C D A F G E H

  5. Solution • CD, GH and EF are all parallel to AB, but only CD passes through D and is parallel to AB. • BC, AD, AE and BF are all perpendicular to AB, but only AD passes through D and is perpendicular to AB • DG, DH, and DE all pass through D and are skew to AB. • Only plane DCH contains D and is parallel to plane ABE

  6. Postulate 13: Parallel Postulate • If there is a line and a point not on the line, then there is exactly one line through the point parallel to the given line. P l

  7. Postulate 14: Perpendicular Postulate • If there is a line and a point not on the line, then there is exactly one line through the given point perpendicular to the given line. P l

  8. Transversal: a line that intersects two or more coplanar lines at different points. Angles 1 and 5 are corresponding angles Angles 1 and 8 are alternate exterior angles Angles 3 and 5 are alternate interior angles. 3 and 5 are consecutive interior angles 1 2 3 4 5 6 7 8 Definitions:

  9. List all pairs of angles that fit the description. Corresponding Alternate exterior Alternate interior Consecutive interior Example 2: Identifying Angle relationships 2 4 1 6 8 3 5 7

  10. Solution: • 1 and 5; 2 and 6; 3 and 7, 4 and 8 • 1 and 8, 2 and 7 • 3 and 6, 4 and 5 • 3 and 5, 4 and 6

  11. Assignment • P. 132 / 10-26, 32-36, 38, 41, 42, 47, 51, 61

More Related