Answer:
<em>290.5 square miles</em>
Step-by-step explanation:
Consider splitting this figure into two mini rectangles and a triangle, each of given lengths;

<em>Solution; 290.5 square miles</em>
Step-by-step explanation:
Here is the solution...hope it helps:)
A negative minus a negative is always a positive ;)
The reflex angle is the other angle
see image below
so
reflex=360-angle
reflex=360-60=300
reflex angle=300