### Video Transcript

What is the intersection of the planes ππ΄π΅ and ππ΅πΆ?

To answer this question, letβs first recall the geometric postulate regarding the intersection of two planes. It tells us that if two planes intersect, then the intersection is a line. So if the planes ππ΄π΅ and ππ΅πΆ do intersect, then the type of intersection weβre looking for is a line.

Letβs now add some shading to the diagram so that we can see these planes more clearly. The plane ππ΄π΅ is now shaded in pink and the plane ππ΅πΆ is now shaded in orange. By doing this, we can see the line that is common to both planes. Itβs the line ππ΅.

Hopefully, youβll find this fairly intuitive as the points π and π΅ are common to both planes. So our answer to the problem is that the intersection of the planes ππ΄π΅ and ππ΅πΆ is the line ππ΅.