Answer:
Approximately [tex]68.5\; \rm mm[/tex].
Step-by-step explanation:
Convert the angle of this sector to radians:
[tex]\begin{aligned}\theta &= 127^{\circ} \\ &= 127^{\circ} \times \frac{2\pi}{360^{\circ}} \\ &\approx 2.22\end{aligned}[/tex].
The formula [tex]s = r\, \theta[/tex] relates the arc length [tex]s[/tex] of a sector of angle [tex]\theta[/tex] (in radians) to the radius [tex]r[/tex] of this sector.
In this question, it is given that the arc length of this sector is [tex]s = 36\; \rm mm[/tex]. It was found that [tex]\theta = 2.22[/tex] radians. Rearrange the equation [tex]s = r\, \theta[/tex] to find the radius [tex]r[/tex] of this sector:
[tex]\begin{aligned} r&= \frac{s}{\theta} \\ &\approx \frac{36\; \rm mm}{2.22} \\ &\approx 16.2\; \rm mm\end{aligned}[/tex].
The perimeter of this sector would be:
[tex]\begin{aligned}& 2\, r + s \\ =\; & 2 \times 16.2\; {\rm mm} + 36\; {\rm mm} \\ =\; & 68.5\; \rm mm\end{aligned}[/tex].
