1. The Vector Equation of a Line The Angle Between 2 Lines 13C

2. The Angle Between 2 Lines The angle between 2 vectors is in the range 0 ≤ θ ≤ 180° b1b1 b2b2 And we used the formula:

3. The Angle Between 2 Lines When the lines go infinitely, we usually refer to the acute angle. So, Cosθ > 0 b1b1 b2b2 And we used the formula: b 1 and b 2 are the direction vectors L1L1 L2L2

4. The Angle Between 2 Lines Find the angle between the lines What do these represent?

5. The Angle Between 2 Lines Find the angle between the lines What do you notice? Since b 1 = b 2, the lines are parallel and the angle between them is 0°

6. The Angle Between 2 Lines Find the ACUTE angle between the lines If a line has a gradient of Then it has a direction vector of

7. The Angle Between 2 Lines

8. Homework Page 327 (1 – 5)

9. The Angle Between 2 Lines