I need a little help what measurement is closest to the area of Nevada in square miles?

Okay so let’s calculate the area of the rectangle at the top first.
A = length(width)
A = (210)(310)
A = 65,100 miles
Now, solve for the triangle at the bottom. First we need to get the height, so..
500 miles - 210 miles = 290 miles
Now we can use the triangle formula
A = base(height)/2
A = 310(290)/2
A = 44,950 miles
Now add our two remaining areas.
44,950 miles + 65,100 miles = 110,050 miles
Therefore, the first option is correct.