You may even remember from high school that the radius is any straight line that starts from the center of the circle and ends at its perimeter. A unit circle is just a circle that has a radius ...

Students are taught the "unit circle" and its relationship to trigonometry, but many fail to make the leap on how crucial circles are for trig functions. With static graphs and equations ...

It just happens that it's easy to show trig functions with a circle, but trig functions are ... So, that's why we have the unit of degrees. What about radians? How about this?

In high school, you probably learned that trigonometric functions – like sine ... (These are only the same value in the case of a unit circle!) This is why the square does not trace a straight ...