$\"\"$

From the figure radius is $\"\"$ and arc length is $\"\"$ .

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

Where,

$\"\"$ central angle and

$\"\"$ = radius of the circle.

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

$\"\"$

Divide each side by 75.

$\"\"$

$\"\"$ radians.

$\"\"$

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