Question: Which way are arrows supposed to point on a tabbed web page? Towards the selection or towards the body of the selection? An awkward scenario seems to arise when a user selects another item and the arrow moves to point at nothing in particular when the arrow is pointing to the body. Is there a best practice? 

![enter image description here](https://i.stack.imgur.com/WgSMw.jpg)

Answer: 
They both look wrong and unecessary. For a tabbed interface the colour of the tab should be the colour of the selected page.
I think the core problem is the arrow or triangle.

Most important is for the tab to stand out from its fellows as the selected tab.

Beyond that is the principle of connection to the content.

One way is to have the content background colour seamlessly flow onto the tab, as shown in Mervin Johnsingh's examples.

If you must have a different coloured protrusion at the bottom of the tab, I suggest you use a small rectangle rather than a triangle. It still emphasises connection as if a tab were taped to the top of the page but gets away from the directional confusion of the arrow.