Question

Explain why there must be at least two lines on any given plane.

Answer 1

Because a plane is defined by lines, it is a two demensional figure and as such it needs at least two lines to be considered a plane.

Answer 2

There exists one plane through any three noncollinear points. Since the points cannot be on the same line, at least two lines would have to pass through any of the three points

Explanation: