Take two toothpicks and while in front of someone, form a triangle by having the toothpicks directly on the desk (/\). Ask a number of people (10 people) if they think you have formed a triangle. If even one person agrees that you have formed a triangle with the two toothpicks, then you will see that humans interpret shapes differently. You don't need 3 toothpicks to form a triangle if you must use the ground (which you must do because the problem requires the ground). Shssh...