If you're not sure what a speed square is, or how you can put yours to good use, this video lesson shows you everything you need to know about one of the best tools out there.
In this video from the This Old House YouTube channel, This Old House general contractor Tom Silva shows how essential the speed square is in a workshop.
With a speed square you can quickly mark 90 and 45 degree edges, use it as a straightedge guide when making cuts, use the pivot point to mark any angle you need, and easily check joints to make sure they're at a precise right angle, and a whole lot more.
You can even use a speed square to draw perfect circles wherever you may need them. Everyone should have one of these in their workshop.
How to Use a Speed Square [YouTube]