Triangle Breathing is a very simple deep breathing technique to help you calm down quickly in a stressful situation.
Doing it can lower your heart rate, relax your abdominal area (where you often feel the tension of stress), and in a more general sense relax your muscles and breathing.
In Triangle Breathing you start with visualizing (imagining) a triangle in your mind. After having done this, you trace the triangle mentally from left to right (starting at the left bottom of the triangle) and count mentally through it with an evenly 1 … 2 … 3 … on inhaling, on holding your breath, and on exhaling.
Said otherwise, while following each part of the triangle mentally, you breathe in slowly for 3 seconds, hold your breath for 3 seconds, and finally exhale slowly for 3 seconds.
You may do “several triangles” (that is, you repeat the session) until you feel relaxed and able to cope with the situation you find (or will find) yourself in.