How do you find the exact value for #tan 120#? Trigonometry Right Triangles Trigonometric Functions of Any Angle 1 Answer sankarankalyanam Mar 17, 2018 #color(indigo)(tan 120 = -sqrt3# Explanation: #hat 120 = hat (120/180) = hat (2pi)/3# Angle falls in II Quadrant and #tan# is negative. #:. tan 120 = tan ((2pi)/3) = tan ((2pi)/3 - pi) = - tan( pi/3)# #- tan (pi/3) = - sqrt 3# Answer link Related questions How do you find the trigonometric functions of any angle? What is the reference angle? How do you use the ordered pairs on a unit circle to evaluate a trigonometric function of any angle? What is the reference angle for #140^\circ#? How do you find the value of #cot 300^@#? What is the value of #sin -45^@#? How do you find the trigonometric functions of values that are greater than #360^@#? How do you use the reference angles to find #sin210cos330-tan 135#? How do you know if #sin 30 = sin 150#? How do you show that #(costheta)(sectheta) = 1# if #theta=pi/4#? See all questions in Trigonometric Functions of Any Angle Impact of this question 68778 views around the world You can reuse this answer Creative Commons License