Scrollbar Trivia

Did you know that the height of a scrollbar in Windows in a ratio of the visible area of a control to the complete height of a control? 

For instance, if you have a a text area control that is 200 pixels high, and it contains a document that needs 800 pixels to be fully visible, then the resulting scrollbar would be 50 pixels high.  Why?

200/800 : 50/200, that’s why. Cool, eh?