Popular California Cities. 1  Long Beach. 2  Los Angeles. 3  San Diego.  San 1  Francisco. San Jose.  Ventura.
The common schoolbook definition of the sine of an angle in a right triangle (which is equivalent to the definition just given) is as the ratio of the lengths of the side of the triangle opposite the angle and the hypotenuse, i.e., (1)
Not to be confused with sign. In mathematics, the sine is a trigonometric function of an angle. The sine of an acute angle is defined in the context of a right triangle: for the specified angle, it is the ratio of the length of the side that is opposite that angle to the length of the longest side of the triangle (the hypotenuse).