How many diagonals can be drawn from one vertex of a decagon?

Oh, dude, a decagon has 10 sides, right? So, if you pick one vertex and want to draw diagonals, you can draw diagonals to all the other vertices except the adjacent ones, which are already sides. So, you can draw 7 diagonals from that one vertex. Math can be fun, like a puzzle... or a headache, depending on how you look at it.