The ornamental design for a venetian blind slathavingdiamond shaped cord holes, as shown and described.
FIG. 1 is a perspective view of the venetian blind slat having diamond shaped cord holes;
FIG. 2 is a front view of the venetian blind slat having diamond shaped cord holes. The rear view of the venetian blind slat having diamond shaped cord holes is a mirror image of the front view shown in FIG. 2;
FIG. 3 is a top view of the venetian blind slat having diamond shaped cord holes. The bottom view of the venetian blind slat having diamond shaped cord holes is a mirror image of the top view of FIG. 3; and,
FIG. 4 is right side view of the venetian blind slat having diamond shaped cord holes. The left side view of the venetian blind slat having diamond shaped cord holes is a mirror image of the right side view of FIG. 4.