Obtuse Angle between Pair of Lines is the angle between any pair of lines which is greater than 90 degrees, in the two dimensional plane. And is denoted by ∠Obtuse. Obtuse Angle between Pair of Lines is usually measured using the Degree for Angle. Note that the value of Obtuse Angle between Pair of Lines is always positive. Typically, the value of Obtuse Angle between Pair of Lines lies in the range from 90 to 180.