I am trying to make a star block.
the 5 pieces I have cut are 5 squares that are all 6 and 1/2 inches sq.
there is one for each corner and one for the center.

Now for the last 4 blocks that I need help with
they are 2 colors and are made of 4 triangles.
Each triangle has the top point of the triangle meeting in the center and the color is every other one. so when placed in the last 4 spots in the block these 4 blocks make the star points.
So basically it is a 9 patch and each of the 9 blocks have to measure 6 1/2 sq before sewn together.

My problem is I dont know what size triangles to cut so when they are all sewn together they equal 6 and 1/2 inch blocks?
Math was not my stong point.

Do you understand what I am saying....I think the block is called teh Ohio Star and if you click on this link you can see what I am trying to make. I just dont know how to do the math...

http://www.quilterscache.com/O/OhioStarBlock.html

I know I can make a paper 6 1/2 inch block and cut it into 4 pieces and add 1/2 inch but is that right? or will it short me?
My brain is to tired and I need help. Thanks in advance.

What you want to do is to make 4 QST's (Quarter Square Triangle blocks). That's what those 4 multi-colored blocks are called.

There are many ways to make these, but the one I prefer the method explained here (see below for measurements):

http://sewhappy10000.blogspot.com/20...orial-tri.html

And ignore the annoying music. ;-)

For future reference, here's the exact calculations:
You want to first cut the squares for these blocks 1.25" larger than the finished size you want (which in this case is 6"), so you would cut them 7.25" and then use the method in the above link.

Now, I ALWAYS make them larger and then cut them down to the exact unfinished size.

So I would cut the squares 7.5" or larger, use the same method in the link, and then trim down to 6.5", which is the unfinished size needed for YOUR Ohio Star block.

Since you mentioned that your QST's are only made of 2 colors, then you would need to start with 2 squares of each color to make the 4 QST's for the block.

The obvious benefit is you never have to deal with triangles or bias edges.

MTS - thanks for writing that info for us. Just last night I was wondering about that.

Thanks for the info, That will work for me. I thought there was some algebra formula I needed and didnt know it. LOL!