Suppose I use a scale on my map where every 3 inches on my map represents 5 miles. If a region on my map has an area of 45 square inches, what is the area of the actual region it represents?

Question

hi I need help with this question, I don't know what to do.

thanks

Answer 1

5 mi/3 in
look at squares on map
5 miles * 5 miles = 3 in * 3 in
so
25 mi^2/9 in^2

45 in^2 * (25 mi^2/9 in^2) = 45*25/9 mi^2

= 125 mi^2

Answer 2

3 in = 5 mi

squaring ... 9 in^2 = 25 mi^2

a = (45/9) * 25 mi^2

Answer 3

but why are we using these numbers.. why are we multiplying or diving??