sine: the trigonometric function that is equal to the ratio of the side opposite a given angle (in a right triangle) to the hypotenuse.
cosine: the trigonometric function that is equal to the ratio of the side adjacent to an acute angle (in a right-angled triangle) to the hypotenuse.
tangent: a straight line or plane that touches a curve or curved surface at a point, but if extended does not cross it at that point.
