Inverted triangle analysis

Hi, I'm going to an English conversation school twice a week in Tokyo, and the class on last Saturday was summarizing English news articles. After the class, my teacher wrote the below note for me, but I could not under stand the part "inverted triangle structure".

Please someone write it in another way. I know I should ask it to him in the next class, but my class is the next Saturday and I really want to know it right now!

Thanks

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Excellent work! Your hard work is paying off!

Generally, there are two kinds of articles in a newspaper. One kind is called an analysis story. Analysis stories almost never follow the hard-news inverted triangle structure. They might begin with an anecdote rather than hard facts. Sometimes, they are even written like an exciting work of fiction!