Calculate the height of a trigon (polygon)?

Question

How can I calculate the height of a trigon? I have three corners (of course, duh) which is named a, b and c. I don't know if it's called "length" in English, but if so, the length of a, b and c doesn't matter. I just need the form. Also explained.

Thank you.

//. Sorry about my English, I'm from Denmark.

Answer 1

Herron's Formula for triangle (trigon)

Height = (2/c)(√(s(s-a)(s-b)(s-c))

where s = (a + b+ c)/2
and a, b, and c are the lengths of the sides, but c is the base from where you are determining height.
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