You need no formulas to answer this question.
Work Step by Step
This question asks us to determine whether a measurement is a measurement of length, area, volume, mass, density, time, or temperature. The measurement is 100,000 km^2. km^2 is a unit of area. We know this because km is a measure of length, but the km^2 indicates it is a measurement of length times another measurement of length. This would result in a measurement of area. There is no real math involved, just memorization of units.