Physiology General 6c3f8e25 Einthoven's triangle, what is the value of lead III when lead I = 2 mv and Lead II =1 mv A 1 B 2 C 3 D 4 High-Yield Explanation According to Einthoven's triangle, voltage in I + III = voltage in II So Voltage in III = II-I = 1-2 = -1 The value is 1.