Radian describes the plane angle subtended by a circular arc as the length of the arc divided by the radius of the arc. One radian is the angle subtended at the center of a circle by an arc that is equal in length to the radius of the circle.
Step 3: Fold the lower left corner up toward the center of the quilt making sure the fold is on the bias. Step 4: Fold the top left corner down toward the center of the quilt making sure the fold is on the bias. Step 5: Making sure the fold is on the bias, fold the top right corner down toward the center of the quilt.
Sew the binding to the quilt with a 1/4-inch seam allowance using a walking foot. Again, remove the pins as you approach them. Do not stitch over the top of any pin. See Binding a Quilt for how to handle the corners, as well as, how to handle the beginning and ending tails of the bias strip.