Connections are lines with special properties. Connections are lines that, when attached to objects, "rubberband" between the objects.
Using the Shape tool allows you to create multiple shapes of the same type quickly. Once you create a shape, you can edit it using the Inspector.
To create a shape using a Palette,
Click-and-drag in a View to create a shape of a specific size. The Shape tool then remembers the size of the last shape it created as the new default size. Ctrl-Shift-click on any instance of a desired shape in a View or Palette to change the type of shape produced by the Shape tool. You can create multiple shapes of the same type very efficiently using the Shape tool.
Select all the shapes (Ctrl-A). Return to the Inspector Shape panel and click on a triangle. You have changed all of the shapes to triangles.