Answer:
The length of the arc is 20 miles.
Explanation:
We know that an arc formed by an angle of 1 radian in a circle of radius of 1 mile will have a length of 1 mile.
If the radius is 5 miles, an arc of 1 radian will have a length of 5 miles.
Then, if the angle is 4 radians, and the radius is 5 miles, we will have an arc length of:
![\text{arc length}=\text {angle} \cdot \text {radius}=4\cdot 5 =20\;\text{miles}](https://img.qammunity.org/2021/formulas/mathematics/college/l0p7rhjb3dpp1wv7hymim9a9l5n72ty02m.png)