The answer is .5 meaning half (1/2) of the petals fell off.
There are 6, you'd think there would be 8 but the answer is actually 6. A diagonal is a line segment that connects to vertices, the two vertices chosen do not count when forming the triangle, two vertices that are adjacent to that chosen vertex are NOT included when forming the diagonal. It's confusing, but I hope this helps. If you have any follow up questions I'd love to answer them.
All of the answer choices that you are given are incorrect. I have calculated it in all different ways and get the same thing and it is none of those. The correct answer would be -75 though.
