
A calculator to find the angle between two lines L_{1} and L_{2} given by their general equation of the form a x + b y = c The formula used to find the acute angle (between 0 and 90°) between two lines L_{1} and L_{2} with slopes m_{1} and m_{2} is given by? = tan^{ 1}( (m_{2}  m_{1}) / (1 + m_{2} × m_{1})) where the slopes m_{1} and m_{2} are given by  b / a for each line.The obtuse angle ? between the same lines is given by ? = 180  ?
1  Use Angle Between two Lines CalculatorEnter the coefficients a,b and c as defined above for lines L1 and L2 as positive real numbers and press "Calculate The Angles". The outputs are the acute and obtuse angles, in DEGREES, between the two lines.
More References and LinksGeneral Equation of a Line: ax + by = c.Equations of Lines in Different Forms. Online Geometry Calculators and Solvers. 