- Move the black points to change the length of segments.
- Observe the diagram for different values of \(a\), \(b\), \(c\) and \(d\) (if they exist).
- Find out the inequality.
- Some apps display tips that help find the solutions. To see them, move from left to right the corresponding point.
- To check your solution, move from left to right the corresponding point.
Remark: After dragging a point from a slider, you may find yourself not able to deselect it. If such a situation occurs (which should be sporadic), just double click on the selected point.