Trims all objects at the cutting edge specified by a selected polyline, line, circle, arc, ellipse, text, mtext, or attribute definition.

Summary:-


After selecting an object and specifying one side of the object, all other objects are trimmed to that object in a single operation.In the following illustration, EXTRIM is started and the large circle is selected as the cutting edge.

Use extrim  on command line to trim very fast

How to trim multiple lines