Part 3/6:
In scenarios where the angle exceeds 90 degrees, it's essential to understand the concept of reference angles, which is the acute angle formed with the x-axis. For example, if faced with an angle like 350 degrees, we recognize that it shares a reference angle of 10 degrees, which impacts our calculations.
When we analyze angles greater than 90 degrees, we start looking at the characteristics of the corresponding sides and how they change:
For angles in the second quadrant (between 90 and 180 degrees), sine remains positive while cosine and tangent are negative.
In the third quadrant (between 180 and 270 degrees), both sine and cosine are negative, while tangent becomes positive.