# Angle between Two Lines

The angle between two lines is the smaller of the angles formed by the intersection of the two lines. The angle can be obtained from:

1. Their slopes

2. Their direction vectors

Find the angle between the lines r and s, if their directional vectors are : = (−2, 1) and = (2, −3).

Given the lines r ≡ 3x + y - 1 = 0 and s ≡ 2x + my - 8 = 0, calculate the value of m so that the two lines form an angle of 45°.