$\"\"$

Arc length of the circle : $\"\"$ .

Here, radius $\"\"$ kilometers and arc length $\"\"$ kilometers.

Substitute the values $\"\"$ km and $\"\"$ in $\"\"$ .

$\"\"$

Divide each side by 80.

$\"\"$

$\"\"$ radians.

$\"\"$

The central angle is $\"\"$ radians.