With C as a center and a radius of 4 inches describe the arc E F, which is the arc of the director circle. Now with the same center and a radius of 3 1/4 inches, describe the arc A B, which is the line of centers of the generating circle as it rolls on the director circle. With O' as a center and a radius of 3/4 inch describe the generating circle. As before, divide the generating circle into any number of equal parts - 12, for instance - and with these points of division L, M, N, 0, etc., draw arcs having C as a center. Upon the arc E F, lay off distances Q R, R S, S T, etc., equal to the chord Q L. Draw radii from the points R, S, T, etc., to the center of the director circle C and describe arcs of circles having a radius equal to the radius of the generating circle, using the points G,I, J, etc., as centers. As in Problem 26, the intersections of the arcs are the points on the hypocycloid. By repeating this process, the right-hand portion of the curve may be drawn.