Answer:
A
I took a picture of your mom and my phone ran out of storage.
Answer:
5.25 miles
Step-by-step explanation:
We are required to determine the distance between Lighthouse A and Lighthouse B in the diagram.
Using Law of Cosines

The distance between lighthouses is 5.25 miles.
The number of 10 chips stacks that Dave can make if two stacks are not considered distinct is 110.
The solution
To get the symmetric stacks, one has to subtract the symmetric stacks to know the ones that are asymmetric.
The symmetric are flipped. Given that they are double counted what we have to do is to divide through by 2.
6/2 = 3
10/2 = 5
4/2 = 2
1/2(10C6) - (5C3) + (5C3)
0.5(210-10+10)
= 110