The given line y = 3 is a horizontal line with slope zero (0).
We wish to find the equation of a line that is perpendicular to y = 3. Such a line would be a vertical one. Vertical lines do not have slopes defined (due to division by zero).
Thus the general form of the equation of this new line is x = c.
This new line passes through (24, -56). Thus, x must be 24: x = 24
