Wedges make circles, but Squedges make squares.

The 18 degree Squedge makes a 16" finished square (16 1/2" unfinished) with 20 Squedge pieces.

The slots in the tool let you mark precise lines for making the shorter pieces. The longer pieces are used for the corners and the shorter for the inner sides.

Open the packaging and you have another Bonus pattern, a terrific table runner, 22" x 72".
Yardage amounts for backing and binding are listed here: backing 1 1/4 yd, binding is 1/2 yd.