Right triangle

Summarize the following text using ONLY facts from it. Do NOT invent references, emails, or links. If the text doesn't mention something, leave it out. A right triangle or right-angled triangle, is a triangle in which two sides are perpendicular, forming a right angle (1⁄4 turn or 90 degrees) The side opposite to the right angle is called the hypotenuse. The sides adjacent to the angle are called legs (or catheti, singular: cathetus) The legs and hypotenused of a right triangle satisfy the Pythagorean theorem: the sum of the areas of the squares on two legs is the area of the square on the hypotensuse. If all three sides of a triangle are the same length, the triangle is called a triple-triangular triangle. The relations between the sides and angles of the triangle provide one way of defining the relations between sides of the right triangle and the angles of a rectangle. The triangle is also known as a Pythagorean triangle, after the Greek word for triangle, Pythagorism.