# Investigating Planes

Create two planes using the "Plane through 3 Points" tool. Use points A, B, and C to create the first plane.
Use points B, C, and D to create the 2nd plane.

Why do you think the tool to create a plane requires 3 points? Why not 2 points? Why not 4 points?

We can name the planes by the 3 points. Name the two planes.

What two points do the planes have in common? Use the rotate tool and look closely at where the planes meet. We call that the intersection. What does the intersection of the two planes look like?

Use the line tool and draw a line through points B and C. Use the rotation tool and take a close look at the intersection.

Points A, B, and C are coplanar because they are on the same plane. Create points E and F that are also coplanar to points A,B, and C using the points tool. Create points G and H that are not coplanar to A,B and C using the points tool.