Open the app you want to use in Split View
Swipe up slightly from the bottom to show the Dock
Touch and hold the second app in the Dock
Drag the app to the left or right edge of the screen
Release it when the screen splits
Adjust the divider to change each app’s size
To replace an app, drag a different app from the Dock into Split View
To close Split View, drag the divider all the way to one side