How to select a good Triangle (Speed square?)

Question

My father is now retired and has returned to his hobby of being a woodworker. He's been helping me build a standing desk for my office and happened to mention while we was working that he wished he had a better triangle.

I would like to buy one for him as a thank you for helping me build the desk, but I don't know what makes a good or bad triangle. He currently has a very solid metal 6" triangle. The only complaint against that one that he has is that is has a little nook as soon as one of the straight edges starts labeled "pivot point" that he says messes up the markings when he's doing small precise work.

How can I select a good triangle, or what makes one good? It's primary purpose will be to get straight edges or angles for woodworking.

Edit: I just found out that these are called speed squares.

Answer 1

For marking right angles, a try square is a good choice.

You might also want to consider a Japanese style square.

Answer 2

From the description, it sounds like you're referring to a rafter square (I've always known it as a speed square):

If he's just looking for straight lines, a combination square may be better for his purposes:

In terms of quality, you frequently get what you pay for. When it comes to a square, look for something that won't easily break or bend. We get cheap plastic squares for the volunteers at the job site, and throw away broken ones all the time. And for one with any moving parts, make sure the joint doesn't have any play in it. The larger the square, the more precise the 90 deg angle will be measured, but it also means that it's more difficult to work with in tight spaces.

If it's a larger framing square, realize that they can be adjusted, even though they are solid metal. This also means that they can be easily knocked out of adjustment if they are abused.