The Epic Interactive Encyclopedia 1997/The_Epic_Interactive_Encyclopedia_97.iso/r/right-angled_triangle/infotext

Text File | 1992-09-02 | 633b | 17 lines

Triangle in which one of the angles is a
right angle (90 degrees ). It is the basic
form of triangle for defining trigonometrical
ratios (for example, sine, cosine, and
tangent) and for which Pythagoras' theorem
holds true. The longest side of a
right-angled triangle is called the
hypotenuse. Its area is equal to half the
product of the lengths of the two shorter
sides. A triangle constructed with its
hypotenuse as the diameter of a circle with
its opposite vertex (corner) on the
circumference is a right-angled triangle.
This is a fundamental theorem in geometry,
first credited to the Greek mathematician
Thales about 580 BC.