Reference Angle is the angle formed by the terminal ray of the original angle and the x-axis.
so, from the diagram we can calaculte it to be...
[tex]\begin{gathered} \text{The value conversion of : }\frac{2\pi}{3}\text{ = }\frac{2\text{ }\times180}{3}\text{ = }\frac{360}{3}=120^o \\ \end{gathered}[/tex]Then the Reference Angle = 180 -120 = 60
[tex]\begin{gathered} u\text{sing sin 60 = }\frac{k}{1} \\ k\text{ = sin 60 }\times1 \\ k\text{ = 0.8666} \\ \text{where k represent the side of the formed Triangle.} \\ \end{gathered}[/tex]sin 60 = 0.86660
cos 60 = 0.5
tan 60 = 1.732
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