Hello, magentarita!

Your forgot to give us the question . . .

Code:

B * * *
o *
* \ *
* \ *
\ x
* \ *
* \ *
* \ *
\ D
* o
* * \ 4
* * \
* o * - - - - - - o L
G 8

The only questions we can answer are:

. . What are the distances amd ?

If that is indeed the question, we should know this theorem:

. . If a tangent and a secant are drawn to a circle from an external point,

. . the tangent is the mean proportional between the external segment

. . of the secant and the entire secant.

In this problem, we have: .

Then: .

Therefore: . miles.