Creating cogs in Illustrator

Thought it worth remembering (although it is very easy) but I wanted to create cogs in Illustrator. Luckily there are lots of youtube videos on the subject, here are two good ones:

and also this one:

The first involves making a circle, drawing a box whose centre is lined up with the circles but is draw on the edge of the circle. This box is then rotated around the centre of the circle by clicking on the box, clicking the rotate tool, and 'alt' clicking on the centre of the circle.

The second involves cutting a circle using rotated and copied lines and circles, and deleting the cog bits from the outside.

I prefer the first method, as cog notches do not wedge shaped the wrong way.