A right-angled triangle is any triangle having one right angle. The side opposite the right angle is called the hypotenuse. A right-angled riangle may be isosceles or scalene.
GalleriesMiscellaneous Right Triangles
V. I. Hallock I.C.S. Refrence Library (Scranton: International Textbook Company, 1905) 20: page 13 in arithmetic section