For this case we have the following scale given: 1 inch: 3 miles
We know that a lake have an area of 18 in^2 and we want to find the actual area of the lake in miles^2
Since we have the conversion factor we can use this and we got::
[tex]18in^2\cdot\frac{(3mi)^2}{(1in)^2}=18in^2\cdot\frac{9mi^2}{1in^2}=162mi^2[/tex]So for this case we can conclude that the answer would be 162 mi^2
