# By Line

[By Line] command extends an existing curve as a straight.

## Step 1

For the prompt "Specify around the end point of a curve", specify by mouse-click around the end point of the curve to extend.

## Step 2

For the prompt "Specify the end point of the line", specify the end point of the extended line.

- Pressing `B` key, the extended line will be doubled by extending the line to both end from the touching point. In this case, the line is generated as a new object without being combined to the original curve.