The side lengths of a right triangle form a so-called Pythagorean triple. A triangle that is not a right triangle is sometimes called an oblique triangle. Special cases of the right triangle include the isosceles right triangle (middle figure) and 30-60-90 triangle (right figure).
The first pacemaker was implanted on 8th October 1958 in a 43 year old man called Arne Larsson with complete heart block and Stokes-Adams attacks. Technological innovations between 1973 and 1980 rendered obsolete the reliable pacemaker of 1970.
The device failed after three hours. A second device was then implanted which lasted for two days. The world's first implantable pacemaker patient, Arne Larsson, went on to receive 26 different pacemakers during his lifetime. He died in 2001, at the age of 86, outliving the inventor as well as the surgeon.