What is the reference angle for #(7pi)/9#? Trigonometry Right Triangles Trigonometric Functions of Any Angle 1 Answer Alan P. Apr 23, 2015 #pi/2< (7pi)/9 < pi# So the reference angle for #(7pi)/9# is #pi - (7pi)/9# #=(2pi)/9# 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 10967 views around the world You can reuse this answer Creative Commons License