Reference angle of 210. Example: If we Free math problem solver answers your algebra, geometry, trigonometry, calculus, and statistics homework questions with step-by-step explanations, just like a math tutor. Sep 1, 2025 ยท Formally, the reference angle of an angle in standard position is the angle formed with the closest portion of the x axis. Make the expression negative because sine is negative in the third quadrant. Thus: Learn how to find reference angles, and see examples that walk through sample problems step-by-step for you to improve your math knowledge and skills. Make the expression negative because cosine is negative in the third quadrant. This is a standard angle; so, we start in the East (to the right or the positive x-axis) and then rotate counterclockwise. The exact value of is . A reference angle is the smallest angle measured to the x-axis. So the reference angle indicated by the the red arc is 210 - 180 = 30 . Plus, learn the reference angle formulas. nb 9h8 7z3uzjlp vokczv fz3zsh sn4u9 lbsu0 q3m oqrqr awm3hjbst