How do you find arctan(−3√) without a calculator?

The value square root of 3 is a value of a special triangle measuring 30-60-90. In this case, we are familiar that the sin of 60 degrees is equal to square root of 3 over 2. and that the cosine of 60 degrees 0.5. tangent is sine over cosine, hence square root of 3 is equivalent. In this case, the answer should be 60 degrees. The negative and positive value inside the parenthesis is the same. 

C. 40,320 just did the math right now