If the figure has a vertex (-1,-3) , than this point lies in third quadrant. If we revolve the figure about x-axis, the symmetry of the figure will lie in the second quadrant whose x-coordinate is negative and y-coordinate is positive i.e, abscissa is negative and ordinate is positive hence the symmetry of the given figure will lie in a second quadrant.
Hence the coordinates of another vertex of the figure is (-1,3).
