# Point, Line, Plane Naming

Undefined terms: A point is a location and is named by a capital letter. A line is made up of points and has no thickness or width. It is named with two letters representing points on the line, or a lowercase script letter. A plane is an infinite flat surface made up of points and is named by a capital script letter or by three letters representing non collinear points on a plane. Collinear points can be contained on a line. Coplanar points can be contained on a plane.
FIRST DIAGRAM: Drag the diagram around by moving the points (you can even make it spin!).

1. Name 3 collinear points. (Turn the diagram if needed)

2. Name 3 noncollinear points:

3. Name a plane.

4. Name in a different way. (Choose all that apply)

Select all that apply
• A
• B
• C
• D
5. Draw , ( ) and then drag it. Notice how the part of the line that is behind the plane is dashed. Draw plane CEA ( ), and then drag it. Then delete the line and plane that you drew.

6. If possible, draw a line through E and C. Are E and C collinear?

Select all that apply
• A
• B

7. If possible, draw a line through E, G, and C. Are E, G, and C collinear?

Select all that apply
• A
• B

8. If possible, name two points that are non collinear, because you CANNOT draw a line through them.

9. If possible, draw a plane through D, B, and F. Are D, B, and F coplanar?

10. If possible, draw a plane through A, G, E, and B. Move the diagram around to see if the four points are on the plane. Are A, G, E, and B coplanar?

11. If possible, name 3 points that are NOT coplanar, because you CANNOT draw a plane through them.

SECOND DIAGRAM: Use points F, D, and E to drag the rectangular prism around. Then answer the following questions.

12. Name the intersection of and .

13. How many planes are in the image?

15. Name two planes that do not intersect.