Circle d has a radius of 21 millimeters and central angle, ∠edf, which measures 60°. find the exact length of . mm 7mm 14mm 42mm

The length of an arc length can be calculated using the formula:
s = ra
where s is the lenght of the arc
and r is the radius of the circle
a is the central angle in radians

first converts degrees to radians
a = 60 ( pi / 180)
a = pi /3 =1.05

s = 21(1.05)
s = 22 mm is the length of the arc