Elementary algebra sign). One of the most well-known equations describes Pythagoras' law relating the length of the sides of a right angle triangle: This equation states that formula_44, representing the square of the length of the side that is the hypotenuse (the side opposite the right angle), is equal to the sum (addition) of the squares of the other two sides whose lengths are represented by formula_45 and formula_46. An equation is the claim that two expressions have the same value and are equal. Some equations are true for all values of the involved variables (such as formula_47); such equations are called
Hypotenuse is the square root of 25, that is, 5. The word "hypotenuse" is derived from Greek (sc. or ), meaning "[side] subtending the right angle" (Apollodorus), The Greek term was loaned into Late Latin, as "hypotēnūsa". Adoption as a learned Latinism used in modern languages dates to the 16th century. The spelling in "-e", as "hypotenuse", is French in origin (Estienne de La Roche 1520). The length of the hypotenuse is calculated using the square root function implied by the Pythagorean theorem. Using the common notation that the length of the two legs of the triangle (the sides perpendicular to