How does Math.tan(x) actually work? (Javascript) : <p>I'm trying to understand the math behind the Math.tan method but it doesn't make any sense. Can someone please explain to me how it works?</p>

<p>Firstly the mathematical formula to solve for a tangent angle is Tangent = Opposite/Adjacent. Which means I need to know two sides of the triangle to figure out the tangent angle. However the Math.tan method only accept a single argument in radians, not the length of two sides, so I don't understand how it's figuring out the angle of the tangent. </p>

<p>Next in examples they show passing impossibly huge radian values into the method and getting back a value. For example, W3 schools shows the example of <code>Math.tan(90)</code> but 90 radians equals 5,156.6 degrees which is an impossible angle for a corner of a right triangle.</p>

<p>How does this method work, what's happening behind the scenes that turns 90 radians into a tangent angle of -1.995200412208242 </p>
