I Was Struggling With Trigonometry Until My Math Teacher Asked Me to Do This

In 1992, I was sitting in a Math classroom, utterly lost. We had been learning Trigonometry for a while, but everything about it felt alien.

What was sine, really? What was cosine supposed to represent? Tangent? Wasn't that supposed to be a straight line? Why were the values so strange — 0.5, sqr(3), sqr(3)/2 ? They seemed like numbers pulled out of a hat. And solving trigonometric equations? That felt like navigating a maze in the dark.

Until one day, my Math teacher gave us a homework assignment:

“Build your own trigonometric circle. With pencil and compass. And take it with you. You’ll use it until you own it.”

 

At first, that last part confused me. Own it? If I built it myself, surely I already owned it?

But I did it anyway. I carefully constructed the circle, adding each key angle and corresponding sine, cosine, and tangent values. I brought it to class. I used it with every single trigonometry question I faced.

And something amazing happened.

After just a short while, I noticed I wasn’t looking at the circle anymore. The angles and values had burned themselves into my mind. I didn’t need the circle — because now, I really owned it.

From that point on, trigonometry stopped being a monster. It became a familiar, even friendly, part of math.

The circle brought together everything that had felt disconnected: the values, the angles, the signs, the unit lengths. Suddenly it all made sense. It wasn’t just a diagram — it was a unifying tool.

Why You Should Build Your Own Trigonometric Circle

Now, as a Math teacher myself, this is my advice to all of you struggling with trigonometry:

Build the circle yourself.

The act of drawing it, labelling it, and using it is where the learning happens.

Just like I did back then, I’m offering you a model trigonometric circle — but only as a guide. Don’t print it. Don’t paste it. Don’t copy it passively.

Take time. Use pencil, compass, and protractor. Build your own.

And then bring it with you. To class. To study sessions. To exam prep.

Until, one day — sooner than you think — you realise you don’t need it anymore.

That’s when you’ll know: you own it.

And from that point forward, trigonometry will never scare you again.

With gratitude to Professor Machado, Escola Secundária Carlos Amarante, Braga, Portugal, 1992.