### Video Transcript

In the following figure, determine the intersection of plane π΄π·π΄ prime and plane π΅π·π΅ prime.

First, letβs identify plane π΄π·π΄ prime. π΄π·π΄ prime, we know that a plane is a flat two-dimensional surface that extends infinitely. And that means that plane π΄π·π΄ prime does not just include this triangular piece. It includes these spaces and continues to extend in all directions.

Letβs go ahead and identify the plane space that includes π΅π·π΅ prime. π΅π·π΅ prime, here is the shape created by π΅π·π΅ prime. And here is a representation of the plane that π΅π·π΅ prime lies in. Hereβs a reduced sketch of these two planes.

We remember that the intersection of two planes is a line. We need to identify the line that is the intersection of these two planes. Line πΆπΆ prime is the intersection of these two planes. What we mean by that is at every point along the line πΆπΆ prime is both plane π΄π·π΄ prime and plane π΅π·π΅ prime.