# Locus #1

- Author:
- Kaitlyn Plate

In the figure below, the "slider" controls the distance from point A to point B. Try moving the slider. What happens to point B?

Try moving point B around the screen. What happens to AB?

Set your slider so that AB = 5 (or as close as you can get it). This means that point B is 5 units away from point A. Move point B to a different location *without* adjusting the slider. The new location of B is also 5 units away from point A.
Right-click on point B and turn the **trace** on. This will show all the places that B goes when you move it.
*Without* adjusting the slider, move point B around the screen. Notice that it always stays 5 units away from point A.
The trace of B shows **the locus of points **that are 5 units from A. What does this locus look like? Be specific. Use appropriate vocabulary.

How would the locus change if we changed AB to 10?