How to Do a Pyramid Graph In Keynote?



I am brand-new to Keynote 2. I am trying to make a pyramid graph or chart, like the old USDA food pyramid, with data inside the pyramid separated by horizontal lines. Just like a pie graph, except it's a pyramid graph!

Anyway, I don't see any options for a pyramid graph in the chart inspector. I see that I can insert a triangle shape and type data into it, but I can't figure out how to separate the data with lines. Can someone guide me through this step by step? Thanks!