Three angles are 72^0, 77^0 & 31^0720,770&310
a / sin A = b / sin B = c / sin CasinA=bsinB=csinC
a / sin 72 = b / sin 77 = 1200 / sin 31asin72=bsin77=1200sin31
:. a = (1200* sin 72) / sin 31 = 2215.8902
b = (1200 * sin 77) / sin 31 = 2270.209
Semi perimeter s = ( a + b + c)/2 = 5686.0991/2 = 2843.0496
s - a = 2843.0496-2215.8902 = 627.1594
s - b = 2843.0496 - 2270.209 = 572.8406
s - c = 2843.0496 - 1200 = 1643.0496
Area of Delta = sqrt(s (s-a) ( s - b) (s - c))
Area = sqrt(2843.0496*627.1594*572.8406*1643.0496)
Area = 1295476.5347
But Area = (1/2) * c * h _c = (1/2) * 1200 * h_c where c is the base.
:. h_c = (1295476.5347* 2) / 1200 = 2159.1276