I have made this block but did it as a paper pieced one. The square in the corner is #1, either triangle beside the square is #2 and the other is #3. The large triangle is #4.
You can make it pretty easy that way any size you draft it to be. Once you have it together, you can always take it back apart and use that for measurements if you wanted to, but I think the paper piece method is easy and gives you nice sharp points.