Use alignment guides in Keynote on iPad
Use alignment and spacing guides to help you place objects precisely. When guides are turned on, they appear as you drag an object on a slide in alignment with, or equidistant to, another object. You can turn the guides off and on as needed.
Turn on alignment guides
Tap , then tap Guides.
Tap to turn on a guide:
Edge Guides: Appear when an object’s edges align with the edges of another object.
Center Guides: Appear when an object’s center aligns with another object or the center of the slide.
Spacing Guides: Indicate when three or more objects are placed equally apart in a line.