Trig isn't one of my strong points, but I'll try to answer.

My text uses this formula and gets a distance of 82.6341 cm. How did they do that?

How does one use this formula and/or convert degrees to measurement?

You're trying to measure the distance d from point P to point Q. In order to do so, you place a bar of known length B such that point Q divides the length of the bar in half.

From the picture above, you can see that

So

I'm not sure if you were asking but to convert angles to decimal degrees it's simply