Here we go how to draw cylinder step by step.
1. Download the Grasshopper program for free in this website: http://www.grasshopper3d.com/page/download-1
2. Open the Rhinoceros program and type for Grasshopper in the comment box. We will see this two box on Rhino
2. Klik the Grasshopper window and choose Surface - Cylinder
3. This is the result of the cylinder in Grasshopper and we also can see in Rhino
4. Change the dimension of the Cylinder. Klik Transform - Number slider.
5. Then connect the "Slider" to the R battery. With this comment we can change the radius of the cylinder.
6. Copy the "Slider" then rename become Height to make another parameter to the cylinder. Then we can change the Radius and Height in different comment.
7. After finish the model klik "Bake" comment from the battery then we find the real model in Rhino.
8. Finish the real model in Rhinoceros (red color)
Have a try ^^