You can add to the length of
a sketch entity (line, centerline, or arc). Use Extend
Entities to extend a sketch entity to meet another sketch entity.
a sketch entity:
In an open
sketch, click Extend Entities on the Sketch toolbar, or click Tools,
changes to .
Move the pointer over the
sketch entity to extend.
The selected entity appears
in red, and a preview appears in red in the direction to extend the entity.
preview extends in the wrong direction, move the pointer to the other
half of the line or arc .
sketch entity to accept the preview.
To extend a sketch entity beyond the closest
entity, click to place the first sketch extension, drag towards the next
sketch entity, then click place the second extension, etc.