# Basic Geometric Postulates Part 2

- Author:
- Ryan Routh, Jan Richter

- Topic:
- Intersection, Planes

If I asked you to identify plane KFE, which plane would that be? Explain in a few sentences why naming a plane with those three letters might be a problem (HINT: if you are stuck go back and look at your notes for the naming rules for planes that we learned).

## Postulate #4: Plane Intersection Postulate

Focus on the intersection of the purple and pink planes. What statement below accurately describes what you see? ONLY CHOOSE ONE ANSWER.

In the diagram above, which points do not lie on either plane?

In the diagram above, which points lie on both planes?

In the diagram above, which points lie on the pink plane?

These questions refer to the above applet. Points are "collinear" if a line COULD be drawn through the named points (the line does not have to actually be there). With that in mind, which of the following are collinear? If you aren't sure, use the line tool to see if a line can be drawn between the two points (click the line tool first THEN click on the two points that you want to draw a line through).

## Postulate #5: Three Points Postulate

When you clicked on three points, a plane appeared in the applet. Is there any other plane that goes through those three points? What statement below accurately describes the situation you see above.

Plane HDI (the new plane you created) intersects plane AFB where?