Question

1.

Answer 1

Circumference is 2πr or πd.
So for part 1 the diameter = 9in.
Plug in 9 into the πd formula.
π*9 = 9π in. ≈ 9*(22/7) ≈ 28.29in

For part 2 (from what I can see) they want you to find the same circumference in centimeters(cm) and use 22/7 for π so first convert the radius to cm.
9 in = 9*2.54 = 22.86cm
Next plug in the values into the Circumference formula: π*d
(22/7)*(22.86) ≈ 71.85cm

Hope this helps!