The ornamental design for an extensioncord with lengthmarkings, as shown and described.
FIG. 1 depicts a front perspective view of an extension cord with length markings showing my new design;
FIG. 2 is a front elevational view of the extension cord of FIG. 1;
FIG. 3 is a rear elevational view of the extension cord of FIG. 2, which is rotated upwardly by 180°;
FIG. 4 is a top plan view of the extension cord of FIG. 2, which is rotated downwardly by 90°; and,
FIG. 5 is a bottom plan view of the extension cord of FIG. 2, which is rotated upwardly by 90°.
In the figures the extension cord is shown with a symbolic break in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design. In the drawings, the broken lines depict environmental subject matter only and form no part of the claimed design.