To convert angles from degrees to radians, multiply the angle by π/180
For angle 126°, the equivalent measurement in radian is:
[tex]\begin{gathered} 126\text{ }\times\frac{\pi}{180} \\ \frac{126\pi}{180} \end{gathered}[/tex]Reduce to the lowest term by dividing the numerator and denominator by 18:
[tex]\begin{gathered} \frac{126\pi\div18}{180\div18} \\ \frac{7\pi}{10} \end{gathered}[/tex]