Wikipedia says this: "the dimension of a mathematical space (or object) is informally defined as the minimum number of coordinates needed to specify any point within it." Say that there is 1D space "contained" within 2D space and the former can be represented as a line in a 2D Cartesian coordinates system. I am under the impression that the line that represents 1D space must be a straight line or else it will "extend" into 2D space and need more than one coordinate to specific any point in it. At this stage (according to the defination above) the line would not be one dimensional. Am I correct?