History [edit]. In 1938, polytetrafluoroethylene (DuPont brand name Teflon) was discovered by accident by a recently hired DuPont Ph.D., Roy J. Plunkett. While working with tetrafluoroethylene gas, he noticed that a previously-pressurized cylinder had no pressure remaining.
Triangle Sides Calculator. This calculator calculates for the length of one side of a right triangle given the length of the other two sides. A right triangle has two sides perpendicular to each other. Sides a and b are the perpendicular sides and side c is the hypothenuse. Enter the length of any two sides and leave the side to be calculated blank. Please check out also the Regular Triangle Calculator and the Irregular Triangle Calculator.
A triangle is a closed figure that has three sides and three angles. The sum of the three angles of every triangle always equals 180Â° . A right triangle always has one angle equal to 90Â° and two angles whose sum is 90Â° , making a total of 180Â° . Rectangles. A rectangle is a four sided shape with four right angles (90Â° ). The sides across from each other are always the same length and always parallel to each other. The four angles add up to a total of 360Â° .