Explicación paso a paso:
longitud de un arco es:
[tex]L = \measuredangle \: central \: \times radio[/tex]
6)
[tex] \measuredangle \: central = \frac{\pi}{3} rad = \alpha [/tex]
[tex]L = 6\pi[/tex]
[tex]r = \frac{L}{ \alpha } \\ \\ r = \frac{6\pi}{ \frac{\pi}{3} } \\ \\ r = \frac{6\pi \times 3}{\pi} \\ \\ r = \frac{18 \not\pi}{ \not\pi} \\ \\ \boxed{r = 18m}[/tex]
b)
[tex]l = \alpha \times r \\ \\ r = \frac{l}{ \alpha } \\ \\ r = \frac{15}{3} \\ \\ r = 5cm[/tex]
espero que sea de tu ayuda
saludos :)
