ANSWER
3.5
EXPLANATION
We want to find the length of the arc that subtends 10pi/9 radians.
To do that, we use the formula for length of an arc:
[tex]\begin{gathered} S\text{ = }\frac{\theta}{2\pi}\cdot\text{ 2}\pi r \\ \text{where r = radius} \\ \theta\text{ = angle (in radians)} \end{gathered}[/tex]
Therefore, we have:
[tex]\begin{gathered} S\text{ = }\frac{\frac{10\pi}{9}}{2\pi}\cdot\text{ 2 }\cdot\text{ }\pi\cdot\text{ 1} \\ S\text{ = }\frac{10\pi}{18\pi}\cdot\text{ 2 }\cdot\text{ }\pi\cdot\text{ 1} \\ S\text{ = 3.5} \end{gathered}[/tex]
That is the length of the arc.
