Final answer:
Einthoven's Triangle forms with the combination of Lead I, Lead II, and Lead III, and it is used to visualize the electrical activity of the heart.
Step-by-step explanation:
Einthoven's Triangle is a concept in the field of medicine and specifically related to the study of electrocardiography. It refers to the formation of a triangle using three lead groups that are used to record electrical activity in the heart. These lead groups are called the limb leads and include Lead I, Lead II, and Lead III.
Lead I is formed by connecting the right arm (RA) and the left arm (LA). Lead II is formed by connecting the right arm (RA) and the left leg (LL). Lead III is formed by connecting the left arm (LA) and the left leg (LL).
By connecting these three lead groups, Einthoven's Triangle is formed, and it is used to visualize the electrical activity of the heart and diagnose various heart conditions.