Using herons formula Now, ar(△ABC) can be calculated by Heron’s Formula, whereAB = a = 30 mBC = b = 30 mAC = c = 48 mSemi Perimeter (s) = a+b+c/2s = 30+38+48/2s = 54 mar(△ABC) = √s(s-a)(s-b)(s-c)= √54(54-30)(54-30)(54-48)= √54×(24)×(24)×(6)= 432 m2Hence, Area of rhombus = 2 × (ar(△))= 2 × 432 = 864 m2Area for 18 cows = 864 m2Area for each cow = 864 / 18 = 48 m2