Automatic Driven Dimensions
If you dimension a closed-profile sketch that would cause an over defined sketch, the dimension is automatically changed to driven.
When you sketch the last entity to create a closed-profile sketch, it may clash with inferred relations from the other sketch entities. In this case, the dimension for the last sketch entity causes the sketch to be over defined. The clashing dimension is changed to a driven dimension.
| The dimension on the left vertical line causes the sketch to be over defined |
| The dimension on the left vertical line that causes the sketch to be over defined is changed to driven |