Geometry (math)
posted by Naila dar .
Identify 2 planes in a triangular prism that intersect.Name their intersection

I suggest you draw the figure, it's easier to see that way. The planes that intersect are:
(1) the plane containing the crosssectional area (one triangle) and the plane containing one lateral surface area (one rectangle); and
(2) the planes containing two lateral surface area (two rectangles)