line N has slope m = 
given a line with slope m then the slope of a line perpendicular to it is
= - 
thus line N has slope -
= 
Answer:
A. 103°
Step-by-step explanation:
57° + 46° =103°
This shows that the third angle in the triangle is 180°-103°=77°
Therefore the largest exterior angle is 180°-77°=103°
area = width * length
or
A = W * L
55 = W * (W+6)
solve for width:
0 = W^2 + 6W - 55
this is a quadratic and has two solutions -11 and 5
a length can only be non-negative so discard -11.
width W = 5 miles
now the length is 5+6 = 11 miles
Coordinates of P are (2,0)