The area of a circle is pi times the radius squared (A = π r²).
Answer:
43 hours
Step-by-step explanation:

y × 9.5 = 408 × 1
9.5y = 408
9.5y ÷ 9.5 = 408 ÷ 9.5

43 hours
Depends on what the measurement is.
Answer:
65.9734457254 or 65.97
Step-by-step explanation:
c= pi x diameter
c= pi x (10.5 x 2)
c= pi x 21
= 65.9734457254