What is tan180°?
The trigonometric ratio of an angle:
In trigonometry, tan of an angle is the ratio of the sine and cosine of the same angle.
tanθ=sinθcosθ
∴tan180°=sin180°cos180°⇒=0-1[∵sin180°=0andcos180°=-1]⇒=0
Hence, tan180°is equal to 0.