triangle question
 

I am not sure what this triangle unit is called but it is 2 small triangles on one side with a large triangle on the other side. My question is- is there an easy way to trim these? I don't have a pattern & I am trying to trim them down to size but don't know where to put my diagonal lines to get a consistent size.
I am sure there has to be an easy way. Can anyone out there help me? Thanks.

This site calls them SQSTs - split quarter square triangles. It has directions for creating and squaring. http://quiltinggallery.com/2014/01/2...g-geese-units/

Or is it a Tri-Rec unit?

https://www.generations-quilt-patter...gle-ruler.html

For FG units I use the Deb Tucker Wing clipper but before I got the wing clipper I made the units to size with no trimming down.

Set your 45 degree line so that the half-way point is at the intersection.
Here my square should be trimmed to 2 1/2" square. T4 the half-way
point is 1 1/4". And make sure that the block meet the 2.5" markings
on each side. Rotate and do the same.

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Hope this helps.

EasyPeezy - thanks so much for posting the photos. I have a bunch of half-squares (none of which seem to be the same size) and this simple explanation will help me immensely to get them all to play nicely together.

It is the SQST unit. thanks so much, dunster for the site suggestion. EasyPeezy thanks for the photos. I knew there had to be an easy answer,but I was stumped on where to put the intersection. Thanks to everyone for the suggestions.

The Quilt in a Day “Triangle Square Up” ruler is so worth the $10 or so. I believe Joann’s carries the original 6” size. With it, you square up before you press them open.

Deb Tucker's trim-down "Tucker Trimmer" works fantastic on these. It's used in the same way as EezyPeezy's example, but there are diagonal lines as well to help you square it. (She calls them "Combination Units.")

The split square triangles are also known as "Boston Blocks" They are very versatile and can be made with all blocks going the same direction or with blocks that are mirror images of themselves.