How do I make one rounded corner

[Seagull]

The reason I continue to visit the forum is to find new ideas, such as Steve just posted. An approach I would never have thought of and it is going into my bag of tricks, which depends on a fading memory unfortunatly.

However, my prefered method is that which "Doc" pointed out, because it is more versatile.
The included image is two rectangles added together, which means you can not use Steve's method. Where I would modify Doc's approch is I create a circle (shown on the Yellow image) and clone it for every corner. This way you have a template to show where to install your points and also drag the 45 degree line to............frank