Angle between two lines

Introduction to Angle between two lines:-

Generally the angle between two lines are measured by when two lines are intersecting each other then there will be a common point to make the angle between the two lines. The angle may be acute or obtuse. When one line intersect the other it creates angle between them, let we see the general diagram for the angle between two lines

An Angle is the figure formed by two rays having common end point. The magnitude of the angle is amount of rotation separating the two rays. The common end point of the rays is called the Vertex.

Let AB and AC be the lines with vertex A. Let be the angle between them.

Angle in terms of Direction Cosines: If l₁, m₁,n₁ represents the direction cosines of line AB and l_2, m₂, n₂ are the direction cosines of line AC, then the angle between the two lines AB and Ac is given by:

cos = l1l2 + m1m2 + n1n2