diketahui alpa sudut lincip. nilai sin alpa dua per tiga, nilai cos alpa .......

[tex] \sin( \alpha ) = \frac{2 }{3} \\ \cos( \alpha ) = \frac{sa}{mi} = \frac{ \sqrt{ {3}^{2} - {2}^{2} } }{3 } = \frac{ \sqrt{5} }{3} [/tex]