Clicking on the relevant tab activates the displays for start or end angle. You can change the rotation angle indicated in the relevant entry field.

Selecting this button opens the Rotate dialog box you are already familiar with. The relevant angle (start or end value) is displayed. You can alter this angle in this dialog box.

Clicking OK returns you to the original rotate dialog box. The new angle you entered in the Rotate dialog box is now indicated here.

When creating the animation using the dialog box, the point in the drawing where you clicked is used as the center point. If you click anywhere on the drawing sheet a center point is generated at this point.

Clicking on the center button opens the following dialog box:

You can specify the coordinate values for the center point of rotation here. As the x and y coordinates have their origin at the bottom left of the drawing sheet, you can specify the center point precisely.