In the History menu area, you can find three basic planes for the construction sketches.

With your right mouse button click on one of these planes (in this case XY) and select the menu point New sketch... in the context menu.

New sketch...

-> This command is opened by the 2-D Sketcher.

In order to create a cylinder you must first draw the basic plane, a circle.

Click on the button Circle with center point and radius/point.

Draw circle

Set a center point by moving the cursor to the KO origin and simply "drop" it with a mouse-click.

When you move your cursor away from the center point, you "pull" the circle "open" and increase its radius. Fix the size with a simple mouse-click as well.

Then the following occurs simultaneously:

Click on the Sketch OK button, in order to confirm your entries.

-> The 2-D Sketcher is closed.

-> In the History area the construction step Sketch 1 shows up.

-> In the 3D view the circle is located on the XY plane.

With your right mouse button, click on Skizze1 and select the command Base, Extrude....

Base -> Extrude...

-> The Extrusion solid window opens.

Set the length (here 20 mm) of the circumference and confirm with OK.[a]
[a] If, in case you want to define the length through a variable value, apply a respective variable "L" in the menu area Variables . Read the following for more information: Section 7.5.3, “ Variables ”.

In the History menu area, in connection with Sketch 1, the construction step Base extrude 1 shows up.

-> In the 3D view the circle is extruded with a value of 20mm to the cylinder.

Cylinder

The save your 3-D sketch.

Click on the Save button.

The Save file as... dialog of the explorer opens.

Set the name and storage location of the geometry and confirm with Save.