Answer:
[tex]110,400\ mi^2[/tex]
Step-by-step explanation:
The picture of the question in the attached figure
we know that
The area of a trapezoid is equal to
[tex]A=\frac{1}{2}[b_1+b_2]h[/tex]
where
b_1 and b_2 are the length of the parallel bases
h is the height (perpendicular distance between the parallel bases)
we have
[tex]b_1=210\ mi\\b_2=480\ mi\\h=320\ mi[/tex]
substitute
[tex]A=\frac{1}{2}[210+480]320=110,400\ mi^2[/tex]