Base × Height:Most basic method when height is known
Area=21×base×height Heron's Formula:When all three sides are known
Area=s(s−a)(s−b)(s−c) SAS Method:Two sides and included angle
Area=21×a×b×sin(C) Circumradius:Using circumscribed circle
Area=4Rabc Inradius:Using inscribed circle
Area=r×s