In the Set Page Boxes dialog box, you can find plenty of options to crop PDF in Adobe Acrobat. The Margin Control options include:CropBox is used to define the borders for the page content when displaying or printing.Constrain Proportions are used to lock the cropping proportions to bring all margins at the same distance.Remove White Margins can be used for cropping a page to the artwork border. It is handy when cropping the edges of presentation slides saved in PDF.Set To Zero allows restoring the cropping margins to zero.Revert To Selection comes in handy when you need to revert the crop margin selected with the Crop Page tool.The Pro version of the program has more options, namely:Show All Boxes is used to highlight the black, red, green, and blue rectangles specifying the CropBox, ArtBox, TrimBox, and BleedBox when previewing. If several margins coincide, you will see just the multicolored lines instead of rectangles.ArtBox helps define the essential content of the page, including white space.TrimBox shows the final size of the page after cropping.BleedBox is used to define the clipping paths when professionally printing a page. Thus, you can trim and fold the sheets. Printing marks may extend beyond the bleed area.