Final answer:
Yes, point C can lie in the same plane as line xy, even if it does not lie on the line.
Step-by-step explanation:
Yes, point C can lie in the same plane as line xy, even if it does not lie on the line. In a 2D Cartesian coordinate system, a plane is defined by two perpendicular lines (axes), one horizontal (x-axis) and one vertical (y-axis). If point C does not lie on line xy, it simply means that it is not located on the line. However, it can still be located within the same plane formed by the x-axis and y-axis.
For example, consider a line xy on a piece of paper. Point C could be located above or below the line, or it could be to the left or right of the line. As long as it is on the same plane defined by the x-axis and y-axis, it is in the same plane as line xy.
Therefore, the location of point C relative to line xy does not determine whether it is in the same plane or not.