Graphically, the histogram provides the value of the mode of the frequency distribution. The rectangle with the greatest height will be the modal class. If we draw a line joining the top right of the rectangle of the modal class with the top right point of the rectangle of the class preceding the modal class and the other line joining the top left point of the rectangle of the modal class with the top left point of the rectangle of the class succeeding the modal class, then the line drawn from the point of intersection of the two diagonal lines will be perpendicular to the X-axis. Thus, the point at which the perpendicular touches the X-axis gives the required modal value.