1. DO NOW! Only things on desk: Work silently & independently Pencil
Handouts you picked up
Work silently & independently

2. To meet, touch, go/cut through, cross, etc.
DO NOW!: Fill in the blank with always, sometimes, or never.
If two planes intersect, then they intersect at a line.
If two lines intersect, then they intersect at two different points.
𝐴𝐵 is another name for 𝐵𝐴 .
Two lines intersect at one point.
One line can be drawn through three points.
In your own words, what does intersect mean?
always
never
always
sometimes
sometimes
To meet, touch, go/cut through, cross, etc.

3. no no yes at point M Yes at point R no
7. Will 𝐽𝑀 and 𝐿𝑄 ever intersect in space? (Lines that intersect on the page do not necessarily intersect in space.) no
8. Will the following pairs of lines intersect in space?
𝐽𝐾 and 𝑁𝑅
𝐿𝑀 and 𝑀𝑅
𝑀𝑅 and 𝑄𝑅
𝐾𝐿 and 𝑁𝑄 no
yes
at point M
Yes at point R no

4. 9. Are the following pairs of lines coplanar?
 This means:
𝐽𝐾 and 𝑅𝑄
𝐽𝑁 and 𝐿𝑅
𝑄𝑅 and 𝑀𝑅
𝐽𝐿 and 𝑁𝑄
Can they lie in the same plane?

5. We will be able to: - Name and describe the 4 different types of lines

6. 2 Lines Oblique Intersecting Perpendicular Parallel Non-Intersecting
are described as…
Oblique
Intersecting
Perpendicular
Parallel
Non-Intersecting
Skew

7. Think about which are coplanar and which are not
With your group, use the provided examples & non-examples to complete the table.
Type of Lines
Characteristics
Picture
OBLIQUE
PERPENDICULAR
SYMBOL:
PARALLEL
SKEW
Think about which are coplanar and which are not

8. Intersecting Oblique Lines
Intersect to form
acute or obtuse angles

9. “Look for the box in a picture! is perpendicular to line l”
Perpendicular Lines
Intersect to form a right angle
Symbol:
Example: j l l j
“Line j
is perpendicular to line l”

10. “Look for the double arrow in a picture!
Parallel Lines A B m n C D
AB is parallel to CD
NEVER intersect
Coplanar
Symbol:
Example: AB CD
“Line AB
is parallel to line CD”

11. Skew Lines NEVER intersect Non-Coplanar m and n are skewB m n C D
m and n are skew
NEVER intersect
Non-Coplanar
a and b are skew

12. Example 1: Think of the sides in the figure as planes.
List all lines parallel to 𝐶𝐷 .
List all lines parallel to 𝐶𝐷 containing point A.
List all lines skew to 𝐶𝐷 .
List all lines skew to 𝐶𝐷 containing point A.
List all lines perpendicular to 𝐶𝐷 .
List all lines perpendicular to 𝐶𝐷 containing point A.
Extension: Name the plane that is parallel to Plane EFG.

13. Example 2: YOUR TURN! List all lines parallel to 𝐸𝐻 . 𝑭𝑮 , 𝑫𝑨
List all lines parallel to 𝐸𝐻 containing point F.
List all lines skew to 𝐸𝐻 .
List all lines skew to 𝐸𝐻 containing point F.
List all lines perpendicular to 𝐸𝐻 .
List all lines perpendicular to 𝐸𝐻 containing point F.
Extension: Name the plane that is parallel to Plane BAH.
𝑭𝑮 , 𝑫𝑨 𝑭𝑮
𝑭𝑪 , 𝑩𝑮 , 𝑨𝑮 , 𝑫𝑪 , 𝑩𝑨 𝑭𝑪
𝑭𝑬 , 𝑯𝑮 , 𝑬𝑫 , 𝑨𝑯 , 𝑭𝑬
Plane CDE

14. Example 3: Think of the sides of a figure as planes.
List all lines parallel to 𝐾𝑁 .
List all lines skew to 𝐽𝑀 .
c) Describe 𝐽𝐾 and 𝑁𝐿 .
𝑱𝑴 and 𝑯𝑳
𝑲𝑯 and 𝑵𝑳
𝒔𝒌𝒆𝒘

15. What is the best description of the horizontal bars in the photo?
INTERSECTING
PERPENDICULAR
SKEW
PARALLEL 𝐎

16. Is the platform perpendicular, parallel, or skew to the ground?
𝐩𝐚𝐫𝐚𝐥𝐥𝐞𝐥

17. Is the arm perpendicular, parallel, or skew to a telephone pole?
𝐬𝐤𝐞𝐰