Let

using a graph tool
see the attached figure
The figure is a triangle
we know that
The Heron's Formula is a method for calculating the area of a triangle when you know the lengths of all three sides.
Hero's Formula is equal to

where
p is is half the perimeter of the triangle
a,b,c are the lengths of the sides of a triangle
so
Step

Find the length sides of the triangle
a) Find the distance AB

Substitute


b) Find the distance AC

Substitute


c) Find the distance BC

Substitute


Step
Find the perimeter of the triangle

Find the half of the perimeter

Step

Find the area of the triangle



therefore
the answer is the option
a) 1.65 mi^2.