Here's how I would do it:

Cut a piece of cardboard or heavy paper to the shape of one point on the cross (Fold it in half and cut one curve [paper-doll style] to keep the curves symmetrical)

Draw a line down the center (Where the fold was)

Draw a second line perpendicular to the first 5" from the top.

Now get a piece of covering and draw two lines at right angles.

Place the template so the lines line-up, and trace it.

rotate 90* and trace again

2 more times and your ready to cut out your cross