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 programmer can also be used to change the controls of the pacemaker. A pacemaker battery usually lasts 7 to 8 years. When the battery runs down, a new pacemaker will be implanted. The surgery to replace the old pacemaker with a new one usually requires a local anesthetic.