Two.
A minimum of 2, but an infinite number of planes can intersect at the same line.
The intersection of two planes forms a line.
Two planes intersect at a line. The line where they intersect pertains to both planes. In the same manner, if infinitely many planes intersect each other at the same line, then that line pertains to the infinitely many planes.
A point can be intersected by infinitely many lines. Two points intersect in only one line. Three points either intersect in a line or not at all. This is only considering two dimensions.
Yes they can. In fact, infinitely many planes can intersect in one line, at least theoretically.
Two distinct planes will intersect in one straight line.
A line segment can be defined as having two endpoints
They need not intersect at all, but if they do, it will be along a straight line and so comprise infinitely many points.
No. Two planes may be parallel and so may not intersect. Also, any line is the intersection of infinitely many planes, not just two.
An 'edge' is the line in which two sides (planes) intersect.
an infinite number; no limit
yes, it may be the two plane intersect at one line or the two planes are coincident.