![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXAzUjZ4YtQLg4qcR-2SdfdUEWk_xMRfGxVsyMPyCGPUGp1Fz4g1oX3hwsHYM_mlKr5HSX1lkeruazj4vvowwUUJpomudNQb3a6v0SDF-qMlrWY2gHgRg4FmLupxe7-Rz_4bMojP4Icw/s320/qgisdangle00.png)
Using the Topology Checker to find dangles is straightforward. Just choose the linear feature layer and define the validation rule(s), and run it. An example usage is illustrated below.
- Start QGIS 2. Load and display a linear feature layer e.g. segments.
- Select Vector | Topology Checker | Topology Checker.
The Topology Checker pane appears on the right. - In the Topology Checker pane, click Configure.
The Topology Rules Settings appear. - In the Current Rules first drop down combo box, choose a linear feature e.g. segments.
The second and/or third combo boxes are enabled. - In the second combo box, choose a validation rule e.g. must not have dangles. Click Add Rule.
The rule is added to the list. - Click OK.
- In the Topology Checker pane, click Validate All.
The dangles are listed. - In the list, select one error.
The dangle is highlighted and centered in the map.