Here's an explanation for "c"
We have two possible congruent right triangles.....
The midpoint of these two coordinates is (0,2) ......the distance from this point to either store is
sqrt [ (3- 0)^2 + (6 - 2)^2 ] = sqrt (9 + 16) = sqrt (25) = 5 miles
And this is one leg of either right triangle......and the other leg is the distance from the warehouse to the road = 4 miles
So.....the distance from the warehouse to either store is the hypotenuse of these triangles
sqrt ( 5^2 + 4^2) = sqrt ( 41) = 6.4 miles
JUST AS HECTICTAR FOUND....!!!!