We must calculate the length of an arc of angle 115°.
We know that the length of an arc of angle 360° is equal to: 2 pi * r.
So we can write the following formula for the lenght of an arc of angle A:
[tex]L=2\pi\cdot r\cdot\frac{A}{360}[/tex]In our problem we have:
A = 115
r = 4 cm
So applying the formula of above the answer is:
[tex]L=2\pi\cdot4\operatorname{cm}\cdot\frac{115}{360}=\frac{23}{9}\cdot\pi\cdot cm\cong8\operatorname{cm}[/tex](rounded to the nearest tenth)
