If you're using a triangular bandage as a sling on an arm, you use it opened out.
You should:
1, Ask the person to hold their arm across their chest and support the arm while you work
2, Put the bandage under the arm and around the back of the neck
3, Put the other half of the bandage over the arm to meet at the shoulder and tie into a knot
4, Tuck the loose ends of the bandage in at the elbow, or use a pin
