### Video Transcript

What is the intersection of the planes ๐๐ด๐ต and ๐๐ต๐ถ?

To answer this question, letโs 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 ๐๐ด๐ต and ๐๐ต๐ถ do intersect, then the type of intersection weโre looking for is a line.

Letโs now add some shading to the diagram so that we can see these planes more clearly. The plane ๐๐ด๐ต is now shaded in pink and the plane ๐๐ต๐ถ is now shaded in orange. By doing this, we can see the line that is common to both planes. Itโs the line ๐๐ต.

Hopefully, youโll find this fairly intuitive as the points ๐ and ๐ต are common to both planes. So our answer to the problem is that the intersection of the planes ๐๐ด๐ต and ๐๐ต๐ถ is the line ๐๐ต.