RIGHT

In Geometry, a term sometimes used synonymously with straight, as right line; but generally as opposed to oblique. Thus, a right angle, the angle formed by two straight lines perpendicular to each other, or an angle of 90'^; right cone, cylinder, prism, pyramid, ., figures whose sides are perpendicular to the plane of the base. Right-angled Triangle. A triangle having one right angle. Right-angled Triangle. In Numbers. A favourite speculation of the Platonic school of mathematicians was to find rational numbers which should designate the sides of a ri^ht-angled triangle. Pythagoras gave the formula a and n'^+l, „, where n is odd. Plato gave 2n, 2 ' 2 ' tc2_i, andn^^. 1, where n is either odd or even. Various other forms have been given by subsequent writers. The determination of such sets of formulee forms a branch of the Diophantine Analysis, [s. 1066]