Trong các mệnh đề sau, mệnh đề nào là sai:
120∘=2π9 rad120{^\circ} = \dfrac{2\pi}{9}\,\,\text{rad}120∘=92πrad.
250∘=25π18rad250{^\circ} = \dfrac{25\pi}{18}\text{rad}250∘=1825πrad.
135∘=3π4rad135{^\circ} = \dfrac{3\pi}{4}\text{rad}135∘=43πrad.
300∘=5π3 rad300{^\circ} = \dfrac{5\pi}{3}\,\text{rad}300∘=35πrad.
120∘=2π9 rad120{^\circ} = \dfrac{2\pi}{9}\,\,\text{rad}120∘=92πrad sai vì 120∘=2π3 rad120{^\circ} = \dfrac{2\pi}{3}\,\,\text{rad}120∘=32πrad
