Use the formula: Central angle = arc length ÷ radius
Use the formula: Central angle = 360° × (arc length ÷ circumference)
Use the formula: Central angle = 360° × (sector area ÷ area of circle)
If the angle is in radians, use: Central angle = arc length ÷ radius
If the angle is in degrees, convert from radians using: degrees = radians × 180 ÷ π
Identify the radius and the arc length or sector area first
Substitute the known values into the appropriate formula
Solve for the central angle
Check that the angle measure matches the required unit: degrees or radians