EXPLANATION :
Note that the intersection of two lines or two segments is a point
The intersection of two planes is a line or a segment
5. Intersection of DC and CB
The intersection as shown in the figure is Point C.
So the answer is point C
6. Name all the planes that are represented.
A plane is a 2-dimensional shape. From the word itself, it can represent as a plane or a sheet.
The planes in the given figure are :
ABC, ACD, ADE, ABE, and BCDE
7. Intersection of plane ABC and plane ACD
The intersection is the common segment between the two planes.
That will be segment AC