drawing: Cylinder with a central hole 1. main form: Draw a cylinder in side vi

drawing: Cylinder with a central hole 1. main form: Draw a cylinder in side view (a rectangle with circular bases at the ends). 2. Finished surfaces: Indicate that the outer part of the cylinder is finished (polished). You can put two dimension lines for the diameter and the height. For example, outer diameter of 50 mm and height of 100 mm. 3. Important center line: Draw a vertical center line that passes through the cylinder, indicating the axis of the cylinder. 4. center hole: Draw a circle in the center of the cylinder. Indicate the diameter of the hole with a dimension line (For example, 20 mm).