What is the length of arc QR?
A. 1/3 π
B. 10/3 π
C. 5/3 π
D. 20/3 π

Answer:
D, 20/3 π
Step-by-step explanation:
10x2=20cm (the diameter)
20xπ = the circumference
120 = 1/3 of 360
20π x 1/3 = 20π/3 or 20/3π