There is no "the" since there are infinitely many non-parallel planes. Two non-parallel planes are planes that intersect in a line.
one
Infinitely many if the 3 distinct points are collinear. Otherwise just 1.
Think you just answered your own question. A plane is a line. Two planes= two lines.
2
Either 0 or 1 plane(s).
There are 10 distinct planes. Each point p1, p2, p3, p4, p5 determines 10 lines: m12, m13, m14, m15, m23, m24, m25, m34,m35, m45 and, therefore 10 planes: p123, p124, p125, p134, p135, p145, p234, p235, p245, p345
There is no "the" since there are infinitely many non-parallel planes. Two non-parallel planes are planes that intersect in a line.
Two distinct planes will intersect in one straight line.
one
Infinitely many if the 3 distinct points are collinear. Otherwise just 1.
Think you just answered your own question. A plane is a line. Two planes= two lines.
One.
2
2
none
3d shapes dont have lines of symmetry. they have planes. since a circle has infinite lines of symmetry, surely a cylinder has infinite planes of symmetry.