# condition of parallel and perpendicular lines

- Author:
- Mathguru

- Topic:
- Straight Lines

We now see that there are two straight lines. Change the slopes of the lines by using the slide bars in such a way that the lines stay parallel.

Questions to think about
1. How are the slopes related, if we want the lines to stay parallel?
2. What do we observe about the angles made by the lines with x-axis?