Question

Three charges-q , q, -q, are placed at the corners of an equilateral triangle of side a

Answer 1

The shape forms an inverted equilateral triangle with the heart at the center. It is named after Willem Einthoven, who theorized its existence. Einthoven used these measuring points, by immersing the hands and foot in pails of salt water, as the contacts for his string galvanometer, the first practical ECG machine.