A 44 inch center on point still has 44 inch side.
So you treat that 44" side as if it were the diagonal of a square or HST block.
These are not exact numbers but within an inch or two.
44" divided by 1.414 = 32"
It would take an approx 32" square to have a diagonal of 44".
To make a big square in a square - but at this size, I'd have the center float - I'd start with two 36" plus (at least) squares.
Cut them in half once on the diagonal.
Attach to two opposite sides of the medallion.
Do not stretch, and remember that they are oversized and will overhang the edges.
Let them.
Pin at the midpoints and gently along the edges.
Sew them on.
Trim the overhang.
Now attach the triangles to the other two sides.
The medallion should be floating within the square made of the triangles.
If you need to, because you cut them oversized, you can square it up.
Keep in mind, you could have always started with bigger squares, which would give you more of a float, and more leeway to square up.
Attach the outer borders as desired.
Keep in mind that this new center will be approx 65" square. Approx.
So you'll still have room to add another 15"plus border all around to get to your desired king size.
My advice - don't try to match the back borders to the front borders (if that was a plan).
It will only lead to heartbreak. :mrgreen:
I would use a huge wide border as the final one on the back.
If you try to match it to something on the front, and the quilting is off, it will look....not great.
Here's a back I did - and I just let it land where ever it was going to.
I think we were off about 2" on side from center - but I think I measured wrong on the back so mea culpa.
But I wasn't trying to match the front of the quilt.