What is the point of trigonometry? Many have asked, and many are still asking. Some say it's all about angles, and they're right. But trig's true mission in life is to help folks make something out of very little information.
Trig was invented to fill gaps in information. How was this done? The math wizards were playing with numbers and triangles, and they had an "aha" moment.
The humble triangle, it turns out, is the building block of most things (as long as they have straight-line boundaries, that is). Take a square, a pentagon, or any other polygon for example. We can chop up each one of those suckers into triangles.
As an example of trig magic, let's take the classing joke: Why did the chicken cross the road? We want to find out the distance between the sitting, squawking chicken (A), the coop (B), and the mound of food (C). Join all points, make a triangle, do some trig calculations and, voilà, we now know a lot more about the distance between the three than we did before. Trig won't help explain why that chicken crossed the road, though. Sorry.