The Break button breaks an entity creating a gap in it.
The Break 
button can be found in the Editor tab under the Instruments section.
Select an entity and press the Break button.
Example 1:
| • | press ; |
| • | select an entity: |
| • | create the gap by two consecutive clicks: |
Example 2 - break a circle:
| • | press Break button; |
| • | select a circle: |
| • | click to set the first break point on the circle: |
| • | click to select the second break point on the circle: |
| • | the result is: |
Note: For circle and ellipse entities Break operation cuts off a sector between the two points in the clockwise direction.