A triangular building is bounded by three streets. The building measures approximately 83 feet on the first​ street, 189 feet on the second​ street, and 178 feet on the third street. Approximate the ground area K covered by the building.
For this case we use Heron's formula to calculate the area of the building.  We have then:  A = root ((s) * (s-a) * (s-b) * (s-c))  Where,  s = (a + b + c) / 2  Substituting values:  s = (83 + 189 + 178) / 2  s = 225 feet  A = root ((225) * (225-83) * (225-189) * (225-178))  A = 7352.509776 feet ^ 2  Rounding off we have:  A = 7353 feet ^ 2  Answer:  The ground area K covered by the building is:  K = 7353 feet ^ 2