Question #9c80e Trigonometry Right Triangles Trigonometric Functions of Any Angle 1 Answer marfre May 1, 2017 #sqrt(3)/2# Explanation: For a #30^@-60^@-90^@ #triangle, the angles are in the ratio: #1: sqrt(3): 2#. #120^@# is in the second quadrant. Sine is positive in this quadrant. Using #soh, sin theta = "opposite"/"hypotenuse" = sqrt(3)/2#. 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 2607 views around the world You can reuse this answer Creative Commons License