hi tyteen4a03

Welcome to the forum.

I've made a diagram. Click below.

You may start by fixing Stockton and Overly at 10 miles apart.

But you don't know exactly where Shea is, in relation to these two.

So I've drawn a circle, radius 8 miles. Shea must lie somewhere on this circle, so you can consider the possibilities by thinking about the nearest it could be and so on.

Hope that helps,

Bob