We have been given diagram of a triangle. We are asked to write an expression that represents the distance between Seattle and San Francisco.
We will use law of cosines to solve our given problem.
, where a, b and c are sides corresponding to angle A, B and C.
Let the distance between Seattle and San Francisco be 'c' and
.
Using law of sines, we can set an equation as:

Upon taking square root in both sides, we will get:

Therefore, we can use the expression
can be used to find distance between Seattle, WA, and San Francisco, CA.