Your issue is that you have no break in the glass so all your blinds will have gaps in them because of the angles.

Drapes will probably your best "close all gaps" but still be able to open up the entire area.

If you used shutters, you wouldn't get to open it all up and I assume you do.

What you can do is get a good curtain rod (not something out of Walmart) and have it bent to angle of the window. We had to do something similar on a commercial job.

Measure the width of th window along the flat edges. then add enough to house your curtains on the side. Add an inch the lenght for each angle (if you have 2 angles, add 2") to accomodate most lost in the bends.

Use a curtain braket on the two ends and then 1 in the middle. Then your can use rings to close the curtains to the middle and cover the entire window.

You are more than welcome to contact me if you need to.

Thanks very much. I didn't know you could bend a curtain rod without ruining it.