Ví dụ minh hoạ:
1) \({30^o} = \frac{{\pi .30}}{{180}} = \frac{\pi }{6}\) rad; 2) \({45^o} = \frac{{\pi .45}}{{180}} = \frac{\pi }{4}\) rad; 3) \({120^o} = \frac{{\pi .120}}{{180}} = \frac{{2\pi }}{3}\) rad.Ví dụ minh hoạ:
1) \(\frac{\pi }{3} = {\left( {\frac{{180}}{\pi }.\frac{\pi }{3}} \right)^o} = {60^o}\); 2) \(\frac{\pi }{2} = {\left( {\frac{{180}}{\pi }.\frac{\pi }{2}} \right)^o} = {90^o}\); 3) \(\frac{{3\pi }}{4} = {\left( {\frac{{180}}{\pi }.\frac{{3\pi }}{4}} \right)^o} = {135^o}\).