Video Transcript
True or False: The vertices of a
triangle determine a plane.
We begin by considering three
points, the vertices of a triangle, which we’ll call 𝐴, 𝐵, and 𝐶. As the three points form a
triangle, this means that they don’t lie on the same straight line. They are noncollinear. One of the geometric postulates
tells us that through any three noncollinear points, there is exactly one plane. The word “exactly” is key. There is only one unique plane that
contains all three points. We can therefore conclude that the
statement “The vertices of a triangle determine a plane” is true.
