Secants and cosecants are ratios of the lengths of two line segments that intersect at a given point. They are used in trigonometry to calculate angles and distances between points. Secants are the ratio of the length of the line segment from the given point to the intersection of the two lines, to the length of the line segment from the given point to the other end of the first line. Cosecants are the ratio of the length of the line segment from the given point to the intersection of the two lines, to the length of the line segment from the given point to the other end of the second line.