Extra Wide Fabric Help Me Out With The Math In My Decorating!?

Help me out with the math in my decorating!? - extra wide fabric

I cover a bed with a canopy and the need to canvas for reducing the back wall.
The wall covering that I need is 69 cm (height) of 78 cm (length).
The material I have is 58 cm (width) x) 126 cm (length.

Unfortunately, the substance is not the right size to hang on the wall, so I cut and re-adjustment (I think I have gained through the wall, because I) extra tissue.

Several inches can be cut and sew together, and you can cut vertically rather than horizontally (to the meeting so that the joints hidden?)

Thank you!