2.52x10^7 people are living in <span>4.05x10^5 km^2 area. then for 1km^2, the number of people can be calculated as: people in 1km^2 = (2.52x10^7) / (</span><span>4.05x10^5) =0.62x10^2 or =6.2x10^1</span>
Pythagorean theorem: a^2 + b^2 = c^2 The hypotenuse is always the c in the equation. If the two side lengths they gave you are not the hypotenuse, then enter 4.5^2 + 5.6^2 in the calculator, then find the square root of that. :-)