Development of the Surface of a Truncated Cylinder:
(a) Sketch the front and top views of a truncated cylinder.
(b) Divide the base circle into an equal number of parts and project the generator on the front view.
(c) Mark the points of intersection as a1, b1, c1, etc, with the generators and the truncated zone of cylinder.
(d) Sketch the stretch-out line equivalent to the circumference of the base of cylinder.
(e) Divide here stretch-out line into the same number of equal parts as that of the base and draw the generators through them.
(f) Situate the points A1, B1, and C1 with a smooth curve.
Notice: The generators must not be drawn thick, as they do not represent the edges on the surface.