In maths, the sine is a trigonometric function of an angle.

  • The sine of an acute angle is defined in the context of a right-angled triangle.
  • In the context of angles and triangles, “acute” refers to an angle that is greater than 0 degrees and less than 90 degrees.
  • For any given angle, its sine is the ratio of the length of the side opposite that angle to the length of the longest side of the triangle (the hypotenuse).
  • The maths notation for sine is sin.