Create Presentation
Download Presentation

Download Presentation
## Points, Lines, and Planes

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

**A point is an exact location in space.**You are here.**A true point has no length, no width, and no height.**In fact, you cannot see a true point.**A point is named by a letter.**Point P P**Lines are 1-dimensional objects that have only length.**Lines continue forever in both directions.**Because a line has no width or height, you cannot see a true**line.**A line is defined by 2 points.**A B Line AB**A ray of light has a starting point (like the sun) and**continues forever in the same direction.**Of course, if the ray hits an object, the light could be**absorbed or reflected. MIRROR**A ray is also defined by 2 points.**C D Ray CD**A line segment has a starting point and an ending point.**Line segments can be measured.**A line segment also defined by 2 points.**E F Line Segment EF**When lines intersect to form right angles, they are said to**be perpendicular. R UT RV c S T U V**Is it possible for lines not to intersect and not be**parallel either?**Believe it or not, this is possible.Let’s consider a**3-dimensional rectangular prism.**These 2 lines are not parallel, but they are not**intersecting either.**You might have heard the word “skewer” the last time you**had a barbecue. S K E W E R**A skewer raises your “dinner” off the surface of the**grill. The skewer does not intersect the grill, and the skewer is not parallel to the grill.**Lines can be…**intersecting skew parallel perpendicular 90º**A plane**is a flat surface that has length & width but no height.**Planes can**intersect.**Planes can**be perpendicular.**Planes can**be parallel.**Planes can be…**intersecting parallel perpendicular