You can set how the rotation feature works by specifying to use a single point of rotation for all lines in your drawing or by specifying to use a separate point of rotation for each line.
For example, when designing a round part such as a flywheel, a single point of rotation will likely be more convenient, whereas a complex device with several moving parts may be more conveniently designed by having separate points of rotation. To specify your preferred setting, check or uncheck the associated checkbox.
To specify how circle sizes are be represented by checking radius or diameter. Generally, diameter is recommended.