Dell Venue 8 Pro (3845, Late 2014) - Manual (Page 19)

Using Your Tablet | 19
Finger gestures Allows you to:
Zoom out
Touch the display with two fingers and
then move the fingers closer. Reduce the view of an image or
web page.
Rotate
Touch the display with two or more
fingers and then move the fingers in a
clockwise or counter‑clockwise arc. Rotate an object by 90 degrees.