Creating triangular UIRegions
<p>I need to separate the screen into regions that look like this (separated by black lines): <a href="https://i.stack.imgur.com/as1bu.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/as1bu.jpg" alt="enter image description here"></a></p>

<p>The documentation says <code>Most regions are rectangular or elliptical in shape, but you can use the methods of this class to create more complex shapes by adding, subtracting, and intersecting other regions.</code> I can't figure out how to create these. </p>

<p>For context I am trying to replicate the <a href="https://developer.apple.com/library/content/samplecode/StickyCorners/Introduction/Intro.html#//apple_ref/doc/uid/TP40016189-Intro-DontLinkElementID_2" rel="nofollow noreferrer">StickyCorners: Using UIFieldBehavior and other UIDynamicBehaviors</a> demo, but adding 4 more sticky points, 1 at each midpoint (indicated by red circles). </p>