Answer
Heron's Formula is useful when only the sides of a triangle are known.
Work Step by Step
Heron's Formula is useful when only the sides of a triangle are known (i.e. no information on height, nor no known information on angles). In real-life situation, this is most often the scenario. Besides, getting the information on the lengths of the sides of a triangle is something that can easily be done, even in real-life setting.
