- By
**lotus** - Follow User

- 272 Views
- Updated On :

Download Presentation
## PowerPoint Slideshow about 'lines and angles' - lotus

**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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

Notes What about lines that don’t intersect and aren’t coplanar? What does it mean for two planes to be parallel?

- What does it mean for two lines to be parallel?
- Parallel lines: Lines that do not intersect and are coplanar.

- Skew Lines: Lines that do not intersect and are not coplanar.

- Parallel Planes:planes that do not intersect.
- Example: the planes containing the ceiling and floor are parallel

Notes

- 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.
- Parallel lines have the same slope (e.g. slope of 3 and 3)
- Tilted at the same angle

- 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.
- Perpendicular Postulate:
- If there is a line and a point not on the line, then there is exactly one line through the point perpendicular to the given line.
- Perpendicular lines have slopes that are negative reciprocals (e.g. 4 and – 1/4)
- At 90 degrees from each other

- If there is a line and a point not on the line, then there is exactly one line through the point perpendicular to the given line.

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 & c

- How about line a?
- b & c

- When a transversal
intersects two lines,

how many angles are

formed?

- 8 angles are formed

Notes

- Angles formed by a transversal.
- We give certain pairs of these angles special names.
- Corresponding Angles: 1 & 5 ; 2 & 6 ; 3 & 7 ; 4 & 8
- Exterior Angles: 1, 2, 7, & 8
- Interior Angles: 3, 4, 5, 6
- Alternate Exterior Angles: 1 & 7 ; 2 & 8
- Alternate Interior Angles: 3 & 5 ; 4 & 6
- Consecutive Interior Angles: 4 & 5 ; 3 & 6

Notes

- Symbols for parallel in statements and figures
- The symbol ll means is parallel to
- The pink arrows on lines PQ and RS indicate that they are parallel.

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 color
- Color the interior angles all one color
- Label the exterior and interior angles

- Using 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.”

- Using another ¼ of a piece of binder paper, draw three lines so that one intersects two of the others.
- 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.

Download Presentation

Connecting to Server..